Add llvm.x86.* intrinsics for Intel SHA Extensions

Add llvm.x86.* intrinsics for all of the Intel SHA Extensions instructions, as
well as tests. Also remove mayLoad and hasSideEffects, which can be inferred
from the instruction patterns.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190864 91177308-0d34-0410-b5e6-96231b3b80d8