fixes #40, extension methods for primitive types

lib/src/checker/resolver.dart

Index: lib/src/checker/resolver.dart
diff --git a/lib/src/checker/resolver.dart b/lib/src/checker/resolver.dart
index 427baf3575f9516954cbb781d8016b0608206271..942eb905022aac0ba740d6c9264099bc182b38c8 100644
--- a/lib/src/checker/resolver.dart
+++ b/lib/src/checker/resolver.dart
@@ -607,9 +607,17 @@ class RestrictedStaticTypeAnalyzer extends StaticTypeAnalyzer {
       // variety of types, especially when we get to JS interop.
       var args = node.argumentList.arguments;
       if (args.isNotEmpty && args.first is SimpleStringLiteral) {
-        var coreLib = _typeProvider.objectType.element.library;
-        var classElem = coreLib.getType(args.first.stringValue);
-        if (classElem != null) node.staticType = classElem.type;
+        var typeStr = args.first.stringValue;
+        if (typeStr == '-dynamic') {
+          node.staticType = _typeProvider.bottomType;
+        } else {
+          var coreLib = _typeProvider.objectType.element.library;
+          var classElem = coreLib.getType(typeStr);
+          if (classElem != null) {
+            var type = fillDynamicTypeArgs(classElem.type, _typeProvider);
+            node.staticType = type;
+          }
+        }
       }
     }
   }