dart2js: Fix crash with reference to type literal in static context.

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 1a1e7d0e49bebad44c1781227fdefbd0a6043097..636270d5fe4e118cf26ded8d76aeb93d1af722ce 100644
--- a/pkg/compiler/lib/src/ssa/builder.dart
+++ b/pkg/compiler/lib/src/ssa/builder.dart
@@ -4139,10 +4139,8 @@ class SsaBuilder extends ResolvedVisitor {
       return readTypeVariable(member.enclosingClass,
                               type.element);
     } else {
-      // TODO(ngeoffray): Match the VM behavior and throw an
-      // exception at runtime.
       compiler.internalError(type.element,
-          'Unimplemented unresolved type variable.');
+          'Unexpected type variable in static context.');
       return null;
     }
   }