Change core lib, dart2js, and more for new optional parameters syntax

lib/compiler/implementation/compiler.dart

Index: lib/compiler/implementation/compiler.dart
===================================================================
--- lib/compiler/implementation/compiler.dart	(revision 13496)
+++ lib/compiler/implementation/compiler.dart	(working copy)
@@ -193,13 +193,13 @@
 
   bool hasCrashed = false;
 
-  Compiler([this.tracer = const Tracer(),
-            this.enableTypeAssertions = false,
-            this.enableUserAssertions = false,
-            this.enableMinification = false,
-            bool emitJavaScript = true,
-            bool generateSourceMap = true,
-            List<String> strips = const []])
+  Compiler({this.tracer: const Tracer(),
+            this.enableTypeAssertions: false,
+            this.enableUserAssertions: false,
+            this.enableMinification: false,
+            bool emitJavaScript: true,
+            bool generateSourceMap: true,
+            List<String> strips: const []})
       : libraries = new Map<String, LibraryElement>(),
         progress = new Stopwatch() {
     progress.start();
@@ -259,8 +259,8 @@
     print(MessageKind.PLEASE_REPORT_THE_CRASH.message([BUILD_ID]));
   }
 
-  void cancel([String reason, Node node, Token token,
-               HInstruction instruction, Element element]) {
+  void cancel(String reason, {Node node, Token token,
+               HInstruction instruction, Element element}) {
     assembledCode = null; // Compilation failed. Make sure that we
                           // don't return a bogus result.
     SourceSpan span = null;