[PATCH] [asan-assembly-instrumentation] Added CFI directives to the generated instrumentation code.

[Yuri Gorshenin]

PTAL

End-to-end test is added in http://reviews.llvm.org/D5260.

================
Comment at: include/llvm/MC/MCTargetAsmParser.h:126
@@ -125,1 +125,3 @@
 
+  virtual void SetFrameRegister(unsigned RegNo) {}
+
----------------
eugenis wrote:
> Please add a comment.
> How does it behave when parsing top-level asm?
> 
Done.

================
Comment at: lib/Target/X86/AsmParser/X86AsmInstrumentation.cpp:557
@@ -529,1 +556,3 @@
+      : X86AddressSanitizer(STI),
+        RegisterInfo(TheX86_64Target.createMCRegInfo(STI.getTargetTriple())) {}
   virtual ~X86AddressSanitizer64() {}
----------------
eugenis wrote:
> Is it the right way to obtain MCRegisterInfo?
> Direct calls to TheXXXTarget seem to be rather uncommon.
> 
It seems that it's possible to get MCRegisterInfo from MCContext, thanks!

http://reviews.llvm.org/D5189