X86: Use btq for bit tests if the immediate can't be encoded in 32 bits.

X86: Use btq for bit tests if the immediate can't be encoded in 32 bits.

Before:
	movabsq	$4294967296, %rax       ## encoding: [0x48,0xb8,0x00,0x00,0x00,0x00,0x01,0x00,0x00,0x00]
	testq	%rax, %rdi              ## encoding: [0x48,0x85,0xf8]
	jne	LBB0_2                  ## encoding: [0x75,A]

After:
	btq	$32, %rdi               ## encoding: [0x48,0x0f,0xba,0xe7,0x20]
	jb	LBB0_2                  ## encoding: [0x72,A]

btq is usually slower than testq because it doesn't fuse with the jump, but here we're better off
saving one register and a giant movabsq.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145103 91177308-0d34-0410-b5e6-96231b3b80d8