Repeats and fixes the changes landed & reverted as CL 1789553003.

pkg/compiler/lib/src/parser/partial_elements.dart

Index: pkg/compiler/lib/src/parser/partial_elements.dart
diff --git a/pkg/compiler/lib/src/parser/partial_elements.dart b/pkg/compiler/lib/src/parser/partial_elements.dart
index d72c6b739766844947c00e838b1337753743555e..b37fe708a27c8d72bf11bd227a842f411db31559 100644
--- a/pkg/compiler/lib/src/parser/partial_elements.dart
+++ b/pkg/compiler/lib/src/parser/partial_elements.dart
@@ -427,7 +427,7 @@ class PartialClassElement extends ClassElementX with PartialElement {
       parsing.measure(() {
         MemberListener listener = new MemberListener(
             parsing.getScannerOptionsFor(this), reporter, this);
-        Parser parser = new ClassElementParser(listener);
+        Parser parser = new ClassElementParser(listener, parsing.parserOptions);
         try {
           Token token = parser.parseTopLevelDeclaration(beginToken);
           assert(identical(token, endToken.next));
@@ -491,7 +491,7 @@ Node parse(
         if (partial.hasParseError) {
           listener.suppressParseErrors = true;
         }
-        doParse(new Parser(listener));
+        doParse(new Parser(listener, parsing.parserOptions));
       } on ParserError catch (e) {
         partial.hasParseError = true;
         return new ErrorNode(element.position, e.reason);