Do not assume that names of function expressions are context-allocated.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 76d8351db1b9225e2486662673023f78cb1c2183..147dc00d4c70e52da5f3469a114b2d940d4cc67d 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -3413,8 +3413,8 @@ class ScopeInfo : public FixedArray {
   // otherwise returns a value < 0. The name must be a symbol (canonicalized).
   int ParameterIndex(String* name);
 
-  // Lookup support for serialized scope info. Returns the
-  // function context slot index if the function name is present (named
+  // Lookup support for serialized scope info. Returns the function context
+  // slot index if the function name is present and context-allocated (named
   // function expressions, only), otherwise returns a value < 0. The name
   // must be a symbol (canonicalized).
   int FunctionContextSlotIndex(String* name, VariableMode* mode);