It can be created by some tools like clangd.

Before the introduction of `Redefine`, `RDefine::InitSlot` did not
recursively call `InitSlot` on its table of defined columns because
it was guaranteed that some other action of filter would do it if
that defined column was ever to be used.

With the introduction of `Redefine`, the only user of a `RDefine`
might be another `RDefine` (`RDefine` serves as the workhorse of both
`Define`s and `Redefine`s), so we have to trigger the recursive call
to `InitSlot` from `RDefine` as well.

This fixes #8857.

Before this commit, we were not testing the case of a Redefine
that overrides a previous Define where the Define also needs to
read some input column.

* Add Conv operator

* Add tests for Conv

* Small fixes

* Add missing default constructor

* Fix typos

* a Python decorator is introduced to set the `_cpp_signature` attribute
  of pythonization functions

* the `print_roofit_pyz_doctrings.py` script now also deals with the
  case where `_cpp_signature` is a list of signatures, adding the
  PyROOT block to the documentaton of each function matched by the
  signatures

* the Python docstring is now used to fill the doxygen documentation
  instead of the `_doxygen` attribute

For the documentation of the RooFit pythonizations, we wanted to realize
two things:

  * A PyROOT block in the doxygen documentation of the C++ class,
    indicating the pythonizations for a given class or function

  * A new doxygen page with only the content of all the RooFit PyROOT
    blocks to have a one-stop place to learn everything about RooFit
    pythonizations

This commit proposes a new mechanism to do this, based on the existing
RooFit pythonization mirror class infrastructure:

  * Every class or member function that should get a PyROOT block gets
    an can be patched with an attribute `_doxygen`, containing the
    contents of the PyROOT block
  * Member functions can also be patched with the attribute
    `cpp_signature`, specifying the C++ overload where the PyROOT block
    should go
  * A new scipt `print_roofit_pyz_doctrings.py` extracts this
    information, and this script is used to create a file
    `_roofit.pyzdoc` with all the doxygen source to generate both the
    PyROOT blocks in the existing documentation, as well as the separate
    page about all the RooFit pythonizations

For unclear reasons the `\cond` directive put _after_ the declaration
of the `ColumnNames_t` alias inhibited docs for it being created.

It is often desirable to call `TChain::Add` with the total number of entries in the file that is being added. This value is retrieved when iterating over the clusters of each file in the chain on the client and then sent as an attribute of the `TTreeRange` to the distributed workers.

Add a new test that checks the invariance of the result from a `Count` operation on a TTree based distributed RDataFrame irrespective of the number of partitions asked. This could have varied in some previously unsupported TEntryList cases.

Tests that check building of `TreeRange` objects now check for all attributes, excluding friend info that has its own separate tests. A test with an input file glob now checks against a full path due to TChain globbing.

This commit changes the way in which an input TTree based dataset is split in logical ranges of entries. It also changes the subsequent creation of an RDataFrame instance inside a distributed task.

For a TTree based dataset, this happens through the creation of a TChain that represents the subset of the original dataset that contains the entries in the range assigned to the task.

Before this commit:

Any `TTreeRange` object would store a `start` and `end` entry attributes that would be global with respect to the TChain created inside
the distributed task. TChain.SetCacheEntryRange(start, end) is called to make sure we don't read more than needed. An RDataFrame is
created with the chain as argument. The Range operation is used to select only the entries of the TChain in the current task that are
described by the input `TTreeRange`.

After this commit:

The input `TTreeRange` will report `globalstart` and `globalend` entries which are global with respect to the TChain of the task. But it
will also report `localstarts` and `localends`, lists of respectively starting and ending entries which are local with respect to each
single file of the TChain in the current task. A global `TEntryList` is created and filled with one sub-TEntryList per file in the chain
through `TEntryList::AddSubList` method. Finally the global entry list is set on the chain via `TChain::SetEntryList` using option
"sync". This allows to do a preselection directly in the TChain of the entries that should be processed or not. SetCacheEntryRange is
still called to ensure we don't read more than needed (hence the need to still keep global entries in the range object). The TChain is
finally passed as argument to an RDataFrame constructor.

Fixes #8141.

Original commit log:"
 We need several adjustments to do. First pre-loading of RInterface.pcm in
 root-project/root@5096f5fffc causes some crashes. Second we seem to still have
 issues when trying to resolve symbols from the Rcpp library.
"

This patch reinstates 28f8835b with adding Rtools and RMVA as part of the
disabled modules

This does not fully disable all dependent modules.

This reverts commit 28f8835b.

Implements `RooLinkedList::begin()`, `end()`, `rbegin()`, `rend()` and
extends the `RooLinkedListIterImpl` interface to support range-based
loops for the `RooLinkedList`.

Range-based loops on `RooLinkedList` are also used in some places in
RooFit to test this new feature. In particular the function
`RooCmdConfig::process` is used in basically every RooFit script.

This commit also adds `RooLinkedList::size()` and `empty()` for better
compatibility with STL containers and automatic pythonizations.

Move the `QUIET` `find_package` option from `SearchInstalledSoftware.cmake` to `FindArrow.cmake`. Thanks to Guilherme Amadio for the suggestion

This new release includes some improvements:
* Extended array support
* Add cmake variables to control the locations where find_package discovers LLVM and Clang: `LLVM_CONFIG_EXTRA_PATH_HINTS` and `Clang_CONFIG_EXTRA_PATH_HINTS` respectively.

See more at: https://github.com/vgvassilev/clad/blob/v0.9/docs/ReleaseNotes.md

ROOT-R: reverted change in macro define introduced in https://github.com/root-project/root/commit/4809ef48e9d3cc48bfe5f81f971a5c535b593b39 for RExports.h

* replace `kTRUE` with `true` and `kFALSE` with `false`

* replace `Double_t` with `double`

* replace `Int_t` with `int` outside of data members

* replace `0` with `nullptr` literals

* replace C-style casts with `static_cast`

* don't generally use `namespace std`

* use `RooAbsCollection::empty()` and `RooAbsCollection::size()` instead
  of `RooAbsCollection::getSize()`

To make the class more readable.

* Silent a couple of potential CMake Warnings

Silent the following warnings when enabling arrow (`-Darrow=ON`) on Ubuntu:
```
CMake Warning at cmake/modules/SearchInstalledSoftware.cmake:20 (_find_package):
  By not providing "Findre2.cmake" in CMAKE_MODULE_PATH this project has
  asked CMake to find a package configuration file provided by "re2", but
  CMake did not find one.

  Could not find a package configuration file provided by "re2" with any of
  the following names:

    re2Config.cmake
    re2-config.cmake

  Add the installation prefix of "re2" to CMAKE_PREFIX_PATH or set "re2_DIR"
  to a directory containing one of the above files.  If "re2" provides a
  separate development package or SDK, be sure it has been installed.
Call Stack (most recent call first):
  /usr/lib/x86_64-linux-gnu/cmake/arrow/Findre2Alt.cmake:25 (find_package)
  cmake/modules/SearchInstalledSoftware.cmake:20 (_find_package)
  /usr/share/cmake-3.16/Modules/CMakeFindDependencyMacro.cmake:47 (find_package)
  /usr/lib/x86_64-linux-gnu/cmake/arrow/ArrowConfig.cmake:96 (find_dependency)
  cmake/modules/SearchInstalledSoftware.cmake:20 (_find_package)
  cmake/modules/FindArrow.cmake:206 (find_package)
  cmake/modules/FindArrow.cmake:313 (arrow_find_package_cmake_package_configuration)
  cmake/modules/FindArrow.cmake:350 (arrow_find_package)
  cmake/modules/SearchInstalledSoftware.cmake:20 (_find_package)
  cmake/modules/SearchInstalledSoftware.cmake:1088 (find_package)
  CMakeLists.txt:245 (include)
```
and
```
CMake Warning at cmake/modules/SearchInstalledSoftware.cmake:20 (_find_package):
  By not providing "Findc-ares.cmake" in CMAKE_MODULE_PATH this project has
  asked CMake to find a package configuration file provided by "c-ares", but
  CMake did not find one.

  Could not find a package configuration file provided by "c-ares" with any
  of the following names:

    c-aresConfig.cmake
    c-ares-config.cmake

  Add the installation prefix of "c-ares" to CMAKE_PREFIX_PATH or set
  "c-ares_DIR" to a directory containing one of the above files.  If "c-ares"
  provides a separate development package or SDK, be sure it has been
  installed.
Call Stack (most recent call first):
  /usr/lib/x86_64-linux-gnu/cmake/arrow/Findc-aresAlt.cmake:25 (find_package)
  cmake/modules/SearchInstalledSoftware.cmake:20 (_find_package)
  /usr/share/cmake-3.16/Modules/CMakeFindDependencyMacro.cmake:47 (find_package)
  /usr/lib/x86_64-linux-gnu/cmake/arrow/ArrowConfig.cmake:96 (find_dependency)
  cmake/modules/SearchInstalledSoftware.cmake:20 (_find_package)
  cmake/modules/FindArrow.cmake:206 (find_package)
  cmake/modules/FindArrow.cmake:313 (arrow_find_package_cmake_package_configuration)
  cmake/modules/FindArrow.cmake:350 (arrow_find_package)
  cmake/modules/SearchInstalledSoftware.cmake:20 (_find_package)
  cmake/modules/SearchInstalledSoftware.cmake:1088 (find_package)
  CMakeLists.txt:245 (include)
```

* Update cmake/modules/SearchInstalledSoftware.cmake

Co-authored-by: Enrico Guiraud <enrico.guiraud@cern.ch>

Co-authored-by: Enrico Guiraud <enrico.guiraud@cern.ch>

We need several adjustments to do. First pre-loading of RInterface.pcm in
root-project/root@5096f5fffc causes some crashes. Second we seem to still have
issues when trying to resolve symbols from the Rcpp library.