Pull in r148240 from upstream llvm trunk:

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

In particular, this fixes segfaults during the build of devel/icu on
i386.  The __sync_synchronize() builtin used for implementing icu's
internal barrier could lead to incorrect behaviour.

MFC after:	3 days

contrib/llvm/lib/Target/X86/X86InstrCompiler.td

@@ -533,7 +533,7 @@ def ATOMSWAP6432 : I<0, Pseudo, (outs GR32:$dst1, GR32:$dst2),
 // 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}",