Object, Mach-O: Refactor and clean code up

Don't assert if we can return an error code, reuse existing
functionality like is64Bit().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221915 91177308-0d34-0410-b5e6-96231b3b80d8
R600/SI: Get rid of FCLAMP_SI pseudo

It's not necessary. Also use complex patterns to allow
src modifier usage.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221916 91177308-0d34-0410-b5e6-96231b3b80d8