Save the MachineFunction in startFunction so that we can use it for
lookups of the subtarget later.

llvm-svn: 229996
diff --git a/llvm/lib/Target/X86/X86AsmPrinter.h b/llvm/lib/Target/X86/X86AsmPrinter.h
index 3a3cbad..d101b8c 100644
--- a/llvm/lib/Target/X86/X86AsmPrinter.h
+++ b/llvm/lib/Target/X86/X86AsmPrinter.h
@@ -57,6 +57,7 @@
     void emitShadowPadding(MCStreamer &OutStreamer, const MCSubtargetInfo &STI);
   private:
     TargetMachine &TM;
+    const MachineFunction *MF;
     std::unique_ptr<MCCodeEmitter> CodeEmitter;
     bool InShadow;