MC: Add support for .cfi_startproc simple

This commit allows LLVM MC to process .cfi_startproc directives when
they are followed by an additional `simple' identifier. This signals to
elide the emission of target specific CFI instructions that would
normally occur initially.

This fixes PR16587.

Differential Revision: http://llvm-reviews.chandlerc.com/D2624

llvm-svn: 200227
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
index a658d1e..0f41b93 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
@@ -113,7 +113,7 @@
   if (!shouldEmitPersonality && !shouldEmitMoves)
     return;
 
-  Asm->OutStreamer.EmitCFIStartProc();
+  Asm->OutStreamer.EmitCFIStartProc(/*IsSimple=*/false);
 
   // Indicate personality routine, if any.
   if (!shouldEmitPersonality)