on darwin empty functions need to codegen into something of non-zero length,
otherwise labels get incorrectly merged.  We handled this by emitting a 
".byte 0", but this isn't correct on thumb/arm targets where the text segment
needs to be a multiple of 2/4 bytes.  Handle this by emitting a noop.  This
is more gross than it should be because arm/ppc are not fully mc'ized yet.

This fixes rdar://7908505



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102400 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86InstrInfo.h b/lib/Target/X86/X86InstrInfo.h
index 3626f96..52a9050 100644
--- a/lib/Target/X86/X86InstrInfo.h
+++ b/lib/Target/X86/X86InstrInfo.h
@@ -693,6 +693,8 @@
                                        int64_t Offset1, int64_t Offset2,
                                        unsigned NumLoads) const;
 
+  virtual void getNoopForMachoTarget(MCInst &NopInst) const;
+
   virtual
   bool ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const;