Revert "[OpenMP] Replace OpenMP RTL Functions With OMPIRBuilder and OMPKinds.def"

Failing tests on Arm due to the tests automatically populating
incomatible pointer width architectures. Reverting until the tests are
updated. Failing tests:

OpenMP/distribute_parallel_for_num_threads_codegen.cpp
OpenMP/distribute_parallel_for_if_codegen.cpp
OpenMP/distribute_parallel_for_simd_if_codegen.cpp
OpenMP/distribute_parallel_for_simd_num_threads_codegen.cpp
OpenMP/target_teams_distribute_parallel_for_if_codegen.cpp
OpenMP/target_teams_distribute_parallel_for_simd_if_codegen.cpp
OpenMP/teams_distribute_parallel_for_if_codegen.cpp
OpenMP/teams_distribute_parallel_for_simd_if_codegen.cpp

This reverts commit 90eaedd.

Author: jhuber6

clang/lib/CodeGen/CGOpenMPRuntime.h

@@ -306,9 +306,6 @@ class CGOpenMPRuntime {
   CodeGenModule &CGM;
   StringRef FirstSeparator, Separator;
 
-  /// An OpenMP-IR-Builder instance.
-  llvm::OpenMPIRBuilder OMPBuilder;
-
   /// Constructor allowing to redefine the name separator for the variables.
   explicit CGOpenMPRuntime(CodeGenModule &CGM, StringRef FirstSeparator,
                            StringRef Separator);
@@ -389,6 +386,8 @@ class CGOpenMPRuntime {
   llvm::Value *getCriticalRegionLock(StringRef CriticalName);
 
 private:
+  /// An OpenMP-IR-Builder instance.
+  llvm::OpenMPIRBuilder OMPBuilder;
 
   /// Map for SourceLocation and OpenMP runtime library debug locations.
   typedef llvm::DenseMap<unsigned, llvm::Value *> OpenMPDebugLocMapTy;