Wrap a recurring question into an interface: getPointerToGlobalFromJIT().

(cherry picked from commit 0b7973cecb915abd7e0add8b907cec6784a30313)

interpreter/cling/lib/Interpreter/ExecutionContext.cpp

@@ -413,3 +413,12 @@ void* ExecutionContext::getAddressOfGlobal(llvm::Module* m,
   }
   return address;
 }
+
+void*
+ExecutionContext::getPointerToGlobalFromJIT(const llvm::GlobalValue& GV) const {
+  if (void* addr = m_engine->getPointerToGlobalIfAvailable(&GV))
+    return addr;
+
+  //  Function not yet codegened by the JIT, force this to happen now.
+  return m_engine->getPointerToGlobal(&GV);
+}

interpreter/cling/lib/Interpreter/ExecutionContext.h

@@ -14,8 +14,9 @@
 #include <set>
 
 namespace llvm {
-  class Module;
   class ExecutionEngine;
+  class GlobalValue;
+  class Module;
 }
 
 namespace clang {
@@ -177,6 +178,13 @@ namespace cling {
     void* getAddressOfGlobal(llvm::Module* m, const char* mangledName,
                              bool* fromJIT = 0) const;
 
+    ///\brief Return the address of a global from the ExecutionEngine (as
+    /// opposed to dynamic libraries). Forces the emission of the symbol if
+    /// it has not happened yet.
+    ///
+    ///param[in] GV - global value for which the address will be returned.
+    void* getPointerToGlobalFromJIT(const llvm::GlobalValue& GV) const;
+
     llvm::ExecutionEngine* getExecutionEngine() const {
       if (!m_engine)
         return 0;