Revert "[CMake] Use a different source depending on C++ support"

This reverts commit r332924 and followup r332936 silencing a warning.

The change breaks the build on x86 if there is no 32-bit version of the
C++ libraries, see discussion in https://reviews.llvm.org/D47169.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@334903 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed