ARM: disable emission of __XYZvfp in soft-float environment.

ARM: disable emission of __XYZvfp in soft-float environment.

The point of these calls is to allow Thumb-1 code to make use of the VFP unit
to perform its operations. This is not desirable with -msoft-float, since most
of the reasons you'd want that apply equally to the runtime library.

rdar://problem/13766161

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206874 91177308-0d34-0410-b5e6-96231b3b80d8