Note regarding C++ for OpenCL:
When compiling C++ for OpenCL, DW_LANG_C_plus_plus* is emitted.
There is no DWARF language code defined for C++ for OpenCL as of yet,
but DWARF issue 210514.1 has been raised to request one.
In the mean time, continuing to emit DW_LANG_C_plus_plus* for C++ for
OpenCL allows the potential to distinguish between C++ for OpenCL and
OpenCL C in !DICompileUnit nodes, whereas using DW_LANG_OpenCL for
C++ for OpenCL would prevent this.
This change therefore leaves C++ for OpenCL as-is.
Reviewed By: shchenz, Anastasia
Differential Revision: https://reviews.llvm.org/D104118
Stuart Brady