AVX-512: added scalar convert instructions and intrinsics.
Fixed load folding in VPERM2I instruction.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192063 91177308-0d34-0410-b5e6-96231b3b80d8
X86: Don't fold spills into SSE operations if the stack is unaligned.

Regalloc can emit unaligned spills nowadays, but we can't fold the
spills into SSE ops if we can't guarantee alignment. PR12250.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192064 91177308-0d34-0410-b5e6-96231b3b80d8
Force a CPU that doesn't have AVX, otherwise this test fails.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192065 91177308-0d34-0410-b5e6-96231b3b80d8