Add a new x86 specific instruction flag to force some isCodeGenOnly instructions to go through to the disassembler tables without resorting to string matches. Apply flag to all _REV instructions.

llvm-svn: 198543
diff --git a/llvm/lib/Target/X86/X86InstrArithmetic.td b/llvm/lib/Target/X86/X86InstrArithmetic.td
index b8d7f9a..fe00b8c 100644
--- a/llvm/lib/Target/X86/X86InstrArithmetic.td
+++ b/llvm/lib/Target/X86/X86InstrArithmetic.td
@@ -752,6 +752,7 @@
     Sched<[WriteALU]> {
   // The disassembler should know about this, but not the asmparser.
   let isCodeGenOnly = 1;
+  let ForceDisassemble = 1;
   let hasSideEffects = 0;
 }
 
@@ -767,6 +768,7 @@
     Sched<[WriteALU]> {
   // The disassembler should know about this, but not the asmparser.
   let isCodeGenOnly = 1;
+  let ForceDisassemble = 1;
   let hasSideEffects = 0;
 }