[X86] Remove references to _ftol2

As of r245924, _ftol2 is no longer used for fptoui on MS platforms.
Remove the dead code associated with it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245925 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed