Support raw types in metadata.

pkg/compiler/lib/src/resolution/resolution.dart

Index: pkg/compiler/lib/src/resolution/resolution.dart
diff --git a/pkg/compiler/lib/src/resolution/resolution.dart b/pkg/compiler/lib/src/resolution/resolution.dart
index 73dd7fedc482cb43a4c6beb238665a7e98f88ee1..0f1837d4c1cf6d595b2874835f1a382c5e02e4d3 100644
--- a/pkg/compiler/lib/src/resolution/resolution.dart
+++ b/pkg/compiler/lib/src/resolution/resolution.dart
@@ -1066,7 +1066,8 @@ class ResolverTask extends CompilerTask {
               switch (constant.kind) {
                 case ConstantExpressionKind.CONSTRUCTED:
                   ConstructedConstantExpression constructedConstant = constant;
-                  if (constructedConstant.type.isGeneric) {
+                  if (constructedConstant.type.isGeneric &&
+                      !constructedConstant.type.isRaw) {
                     // Const constructor calls cannot have type arguments.
                     // TODO(24312): Remove this.
                     reporter.reportErrorMessage(