Reland of Preparse inner functions (new try)

src/parsing/parser.h

Index: src/parsing/parser.h
diff --git a/src/parsing/parser.h b/src/parsing/parser.h
index 74fb5dd5b2d96c20a96e6dc2ddc8f0a745f6aa5f..c953796dc671ce9158773591bda45613ac81ff6e 100644
--- a/src/parsing/parser.h
+++ b/src/parsing/parser.h
@@ -484,10 +484,11 @@
   // in order to force the function to be eagerly parsed, after all.
   LazyParsingResult SkipLazyFunctionBody(int* materialized_literal_count,
                                          int* expected_property_count,
-                                         bool may_abort, bool* ok);
+                                         bool is_inner_function, bool may_abort,
+                                         bool* ok);
 
   PreParser::PreParseResult ParseLazyFunctionBodyWithPreParser(
-      SingletonLogger* logger, bool may_abort);
+      SingletonLogger* logger, bool is_inner_function, bool may_abort);
 
   Block* BuildParameterInitializationBlock(
       const ParserFormalParameters& parameters, bool* ok);
@@ -1063,6 +1064,9 @@
   }
 
   // Parser's private field members.
+  friend class DiscardableZoneScope;  // Uses reusable_preparser_.
+  // FIXME(marja): Make reusable_preparser_ always use its own temp Zone (call
+  // DeleteAll after each function), so this won't be needed.
 
   Scanner scanner_;
   PreParser* reusable_preparser_;