Refactor muldf3 and mulsf3.

Patch from: GuanHong Liu
Differential Revision: http://reviews.llvm.org/D3886

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@209741 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed