Fix JS minifier to lift var declarations within functions. Still disabled.

tests/compiler/dart2js/code_motion_test.dart

Index: tests/compiler/dart2js/code_motion_test.dart
diff --git a/tests/compiler/dart2js/code_motion_test.dart b/tests/compiler/dart2js/code_motion_test.dart
index 0c71c9943b76a1fdb8f8438bdeb019802dd29a46..f093b7a977ce5d29d433454d27250f0aeedf7517 100644
--- a/tests/compiler/dart2js/code_motion_test.dart
+++ b/tests/compiler/dart2js/code_motion_test.dart
@@ -5,13 +5,13 @@
 #import("compiler_helper.dart");
 
 const String TEST_ONE = r"""
-foo(int param0, int param1, bool param2) {
+foo(int a, int b, bool param2) {
   for (int i = 0; i < 1; i++) {
-    var x = param0 + 5;  // '+' is now GVNed.
+    var x = a + 5;  // '+' is now GVNed.
     if (param2) {
-      print(param0 + param1);
+      print(a + b);
     } else {
-      print(param0 + param1);
+      print(a + b);
     }
   }
 }
@@ -19,7 +19,7 @@ foo(int param0, int param1, bool param2) {
 
 main() {
   String generated = compile(TEST_ONE, 'foo');
-  RegExp regexp = const RegExp('param0 \\+ param1');
+  RegExp regexp = const RegExp('a \\+ b');
   Iterator matches = regexp.allMatches(generated).iterator();
   Expect.isTrue(matches.hasNext());
   matches.next();