WIP: Compute constant expressions in resolution.

pkg/compiler/lib/src/elements/modelx.dart

Index: pkg/compiler/lib/src/elements/modelx.dart
diff --git a/pkg/compiler/lib/src/elements/modelx.dart b/pkg/compiler/lib/src/elements/modelx.dart
index 0f434f34706a722ecb79d16e9e54d452473fff19..3fe0301dfe636992f7144b3e43358a525d523fbc 100644
--- a/pkg/compiler/lib/src/elements/modelx.dart
+++ b/pkg/compiler/lib/src/elements/modelx.dart
@@ -2154,9 +2154,12 @@ abstract class ConstantConstructorMixin implements ConstructorElement {
       return originConstructor.constantConstructor;
     }
     if (!isConst || isFromEnvironmentConstructor) return null;
-    if (_constantConstructor == null) {
+    assert(invariant(this,
+        _constantConstructor != null,
+        message: "Constant constructor has not been computed for $this."));
+    /*if (_constantConstructor == null) {
       _constantConstructor = computeConstantConstructor(resolvedAst);
-    }
+    }*/
     return _constantConstructor;
   }