Use int3 trap padding between functions instead of trapsleds with a leading jump.

Index: lib/Target/X86/X86AsmPrinter.h
--- lib/Target/X86/X86AsmPrinter.h.orig
+++ lib/Target/X86/X86AsmPrinter.h
@@ -128,6 +128,8 @@ class LLVM_LIBRARY_VISIBILITY X86AsmPrinter : public A
 
   void emitInstruction(const MachineInstr *MI) override;
 
+  void emitTrapToAlignment(Align Alignment) const override;
+
   void emitBasicBlockEnd(const MachineBasicBlock &MBB) override {
     AsmPrinter::emitBasicBlockEnd(MBB);
     SMShadowTracker.emitShadowPadding(*OutStreamer, getSubtargetInfo());