Change the sysexit mnemonic (and sysexitl) to never have the REX.W prefix and
not depend on In32BitMode.  Use the sysexitq mnemonic for the version with the
REX.W prefix and only allow it only In64BitMode.  rdar://9738584

llvm-svn: 143112
diff --git a/llvm/test/MC/X86/x86_errors.s b/llvm/test/MC/X86/x86_errors.s
index 054331a..8de7444 100644
--- a/llvm/test/MC/X86/x86_errors.s
+++ b/llvm/test/MC/X86/x86_errors.s
@@ -18,3 +18,5 @@
 
 movl 0(%rax), 0(%edx)  // error: invalid operand for instruction
 
+// 32: error: instruction requires a CPU feature not currently enabled
+sysexitq