[X86] Turn (and (anyextend (shl X, C1), C2)) into (shl (and (anyextend X), (C1...

[X86] Turn (and (anyextend (shl X, C1), C2)) into (shl (and (anyextend X), (C1 >> C2), C2) if the AND could match a movzx.

There's one slight regression in here because we don't check that the immediate
already allowed movzx before the shift. I'll fix that next.

llvm-svn: 358804