Merged: Fix function name inference corruption for async functions

src/parsing/func-name-inferrer.cc

Index: src/parsing/func-name-inferrer.cc
diff --git a/src/parsing/func-name-inferrer.cc b/src/parsing/func-name-inferrer.cc
index 0821be0a68a623012df807fb948990a1b38ca5d9..a86e1c299fe28b2afd59b73a00cf661f8a1dd54e 100644
--- a/src/parsing/func-name-inferrer.cc
+++ b/src/parsing/func-name-inferrer.cc
@@ -45,9 +45,11 @@ void FuncNameInferrer::PushVariableName(const AstRawString* name) {
 }
 
 void FuncNameInferrer::RemoveAsyncKeywordFromEnd() {
-  DCHECK(names_stack_.length() > 0);
-  DCHECK(names_stack_.last().name->IsOneByteEqualTo("async"));
-  names_stack_.RemoveLast();
+  if (IsOpen()) {
+    DCHECK(names_stack_.length() > 0);
+    DCHECK(names_stack_.last().name->IsOneByteEqualTo("async"));
+    names_stack_.RemoveLast();
+  }
 }
 
 const AstString* FuncNameInferrer::MakeNameFromStack() {