[VE] Add standard include path and library path for C++

We have a plan to add libcxx and libcxxabi for VE.  In order to do so,
we need to compile cxx source code with bootstarapped header files.
This patch adds such expected path to make clang++ work, at least
not crash at the startup.  Add regression test for that, also.

Reviewed By: simoll

Differential Revision: https://reviews.llvm.org/D92386