WIP: Compute constant expressions in resolution.

pkg/compiler/lib/src/types/constants.dart

Index: pkg/compiler/lib/src/types/constants.dart
diff --git a/pkg/compiler/lib/src/types/constants.dart b/pkg/compiler/lib/src/types/constants.dart
index 112946520776b3fbf217c5ad5201982b698a3815..6567b5a3041008e3125136eec74f55c1f06f00a2 100644
--- a/pkg/compiler/lib/src/types/constants.dart
+++ b/pkg/compiler/lib/src/types/constants.dart
@@ -115,4 +115,10 @@ class ConstantValueTypeMasks extends ConstantValueVisitor<TypeMask, Compiler> {
   TypeMask visitType(TypeConstantValue constant, Compiler compiler) {
     return compiler.typesTask.typeType;
   }
+
+  @override
+  TypeMask visitNonConstant(NonConstantValue constant,
+                            Compiler compiler) {
+    return compiler.typesTask.dynamicType;
+  }
 }