[LibCallSimplifier] don't get fooled by a fake fmin()

This is similar to the bug/fix:
https://llvm.org/bugs/show_bug.cgi?id=26211
http://reviews.llvm.org/rL258325

The fmin() test case reveals another bug caused by sloppy
code duplication. It will crash without this patch because
fp128 is a valid floating-point type, but we would think
that we had matched a function that used doubles.

The new helper function can be used to replace similar
checks that are used in several other places in this file.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258428 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed