dart2js: move type-mask intermediate data from tree-elements into the global

tests/compiler/dart2js/concrete_type_inference_test.dart

Index: tests/compiler/dart2js/concrete_type_inference_test.dart
diff --git a/tests/compiler/dart2js/concrete_type_inference_test.dart b/tests/compiler/dart2js/concrete_type_inference_test.dart
index e3833ad61c39827fcd16fc5898222a45b2f30ee7..29317ae159e08c956c225c3e3e0d3f6734b6781b 100644
--- a/tests/compiler/dart2js/concrete_type_inference_test.dart
+++ b/tests/compiler/dart2js/concrete_type_inference_test.dart
@@ -20,24 +20,21 @@ void checkPrintType(String expression, checkType(compiler, type)) {
   asyncTest(() => compileAndFind('main() { print($expression); }', 'print',
           (compiler, printElement) {
         var parameter = printElement.functionSignature.requiredParameters.first;
-        var type = compiler.globalInference.results.typeOf(parameter);
-        checkType(compiler, type);
+        checkType(compiler, _typeOf(compiler, parameter));
       }));
 
   asyncTest(() =>
       compileAndFind('main() { var x = print; print($expression); }', 'print',
           (compiler, printElement) {
         var parameter = printElement.functionSignature.requiredParameters.first;
-        var type = compiler.globalInference.results.typeOf(parameter);
-        checkType(compiler, type);
+        checkType(compiler, _typeOf(compiler, parameter));
       }));
 
   asyncTest(() => compileAndFind(
           'main() { print($expression); print($expression); }', 'print',
           (compiler, printElement) {
         var parameter = printElement.functionSignature.requiredParameters.first;
-        var type = compiler.globalInference.results.typeOf(parameter);
-        checkType(compiler, type);
+        checkType(compiler, _typeOf(compiler, parameter));
       }));
 }
 
@@ -72,13 +69,9 @@ void testOptionalParameters() {
     var secondParameter = fiskElement.functionSignature.optionalParameters[0];
     var thirdParameter = fiskElement.functionSignature.optionalParameters[1];
     var commonMasks = compiler.commonMasks;
-    var inference = compiler.globalInference;
-    Expect.identical(
-        commonMasks.uint31Type, inference.results.typeOf(firstParameter));
-    Expect.identical(
-        commonMasks.nullType, inference.results.typeOf(secondParameter));
-    Expect.identical(
-        commonMasks.nullType, inference.results.typeOf(thirdParameter));
+    Expect.identical(commonMasks.uint31Type, _typeOf(compiler, firstParameter));
+    Expect.identical(commonMasks.nullType, _typeOf(compiler, secondParameter));
+    Expect.identical(commonMasks.nullType, _typeOf(compiler, thirdParameter));
   });
 }
 
@@ -86,3 +79,6 @@ void main() {
   testBasicTypes();
   testOptionalParameters();
 }
+
+_typeOf(compiler, parameter) =>
+    compiler.globalInference.results.resultOf(parameter).type;