CodeGen: Initial instrumentation based PGO implementation

llvm-svn: 198640
diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 8cc61e9..4bdd032 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -2184,6 +2184,7 @@
     call->setCallingConv(getRuntimeCC());
     Builder.CreateUnreachable();
   }
+  PGO.setCurrentRegionCount(0);
 }
 
 /// Emits a call or invoke instruction to the given nullary runtime