Add an internal flag to the dart2js compiler to enable/diable inlining

tests/compiler/dart2js/call_site_type_inferer_test.dart

Index: tests/compiler/dart2js/call_site_type_inferer_test.dart
diff --git a/tests/compiler/dart2js/call_site_type_inferer_test.dart b/tests/compiler/dart2js/call_site_type_inferer_test.dart
index cd9cc6b7a79b000fbe7e57e0fcf27f01c37c5c92..b707ac6b6c111b455fd10463b62c72ebcf1ae550 100644
--- a/tests/compiler/dart2js/call_site_type_inferer_test.dart
+++ b/tests/compiler/dart2js/call_site_type_inferer_test.dart
@@ -14,9 +14,11 @@
 void compileAndFind(String code,
                     String className,
                     String memberName,
+                    bool enableInlining,
                     check(compiler, element)) {
   Uri uri = new Uri.fromComponents(scheme: 'source');
   var compiler = compilerFor(code, uri);
+  compiler.enableInlining = enableInlining;
   compiler.runCompiler(uri);
   var cls = findElement(compiler, className);
   var member = cls.lookupLocalMember(buildSourceString(memberName));
@@ -189,13 +191,15 @@ const String TEST_17 = @"""
   }
 """;
 
-void runTest(String test,
-             [List<HType> expectedTypes,
-              OptionalParameterTypes defaultTypes]) {
+void doTest(String test,
+            bool enableInlining,
+            List<HType> expectedTypes,
+            OptionalParameterTypes defaultTypes) {
   compileAndFind(
     test,
     'A',
     'x',
+    enableInlining,
     (backend, x) {
       HTypeList types = backend.optimisticParameterTypes(x, defaultTypes);
       if (expectedTypes != null) {
@@ -207,6 +211,13 @@ void runTest(String test,
   });
 }
 
+void runTest(String test,
+             [List<HType> expectedTypes,
+              OptionalParameterTypes defaultTypes]) {
+  doTest(test, true, expectedTypes, defaultTypes);
+  doTest(test, false, expectedTypes, defaultTypes);
+}
+
 void test() {
   OptionalParameterTypes defaultTypes;