simplifylibcalls optimization is thus valid for C++ but not C.
It's not important enough to worry about for C++ apps, so just
remove it.
rdar://7191924
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80887 91177308-0d34-0410-b5e6-96231b3b80d8