[PATCH 1/2] Make C++ compiler configurable

The C++ compiler used to build prepare-builtins
may differ from the llvm/clang for which we are
building libclc.

Use 'c++' as the default compiler.

Gentle ping.

Thanks,

Jeroen

The C++ compiler used to build prepare-builtins
may differ from the llvm/clang for which we are
building libclc.

Use 'c++' as the default compiler.

Sorry, this patch was dropped.

I think the default compiler should be clang++ in order to preserve
the existing behavior. If you agree, I will make this change before I
push. (I will push your other patch too).

-Tom