Make sure the non-SSE lowering for fences correctly clobbers EFLAGS.  PR11768.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148240 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86InstrCompiler.td b/lib/Target/X86/X86InstrCompiler.td
index 5649ba5..1106b85 100644
--- a/lib/Target/X86/X86InstrCompiler.td
+++ b/lib/Target/X86/X86InstrCompiler.td
@@ -551,7 +551,7 @@
 // Memory barriers
 
 // TODO: Get this to fold the constant into the instruction.
-let isCodeGenOnly = 1 in
+let isCodeGenOnly = 1, Defs = [EFLAGS] in
 def OR32mrLocked  : I<0x09, MRMDestMem, (outs), (ins i32mem:$dst, GR32:$zero),
                       "lock\n\t"
                       "or{l}\t{$zero, $dst|$dst, $zero}",