Revert two Kernel changes that were causing test failures.

tests/language/assertion_test.dart

+// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+// VMOptions=--enable_asserts
+//
+// Dart test program testing assert statements.
+
+import "package:expect/expect.dart";
+
+class AssertionTest {
+  static testTrue() {
+    int i = 0;
+    try {
+      assert(true);
+    } on AssertionError catch (error) {
+      i = 1;
+    }
+    return i;
+  }
+
+  static testFalse() {
+    int i = 0;
+    try {
+      assert(false);
+    } on AssertionError catch (error) {
+      i = 1;
+    }
+    return i;
+  }
+
+  static unknown(var a) {
+    return (a) ? true : false;
+  }
+
+  static testUnknown() {
+    var x = unknown(false);
+    int i = 0;
+    try {
+      assert(x);
+    } on AssertionError catch (error) {
+      i = 1;
+    }
+    return i;
+  }
+
+  static testClosure() {
+    int i = 0;
+    try {
+      assert(() => false);
+    } on AssertionError catch (error) {
+      i = 1;
+    }
+    return i;
+  }
+
+  static testClosure2() {
+    int i = 0;
+    try {
+      var x = () => false;
+      assert(x);
+    } on AssertionError catch (error) {
+      i = 1;
+    }
+    return i;
+  }
+
+  static testMain() {
+    Expect.equals(0, testTrue());
+    Expect.equals(1, testFalse());
+    Expect.equals(1, testClosure());
+    Expect.equals(1, testClosure2());
+  }
+}
+
+main() {
+  AssertionTest.testMain();
+}