Fix boolean conversion bug in dart2js + update JSRegExp accordingly.

pkg/compiler/lib/src/ssa/builder.dart

Index: pkg/compiler/lib/src/ssa/builder.dart
diff --git a/pkg/compiler/lib/src/ssa/builder.dart b/pkg/compiler/lib/src/ssa/builder.dart
index e3cb4b8d7da65c624767601c97c750cc201c07c7..0f5199287baf9082ade8007d022b1fbaabd75e3d 100644
--- a/pkg/compiler/lib/src/ssa/builder.dart
+++ b/pkg/compiler/lib/src/ssa/builder.dart
@@ -493,9 +493,7 @@ class LocalsHandler {
         }
       }
       HInstruction value = directLocals[local];
-      if (false && sourceInformation != null) {
-        // TODO(johnniwinther): Enable this again when boolean conversions of
-        // boolean type conversions are handled correctly.
+      if (sourceInformation != null) {
         value = new HRef(value, sourceInformation);
         builder.add(value);
       }