Make running test possible with CMD.exe

Needed to use a .bat file to avoid an issue
where built-in modules shadowed the R8-defined
modules with same names.

Bug:

Change-Id: Ia18c011bf1968ece440251d17074d2a76b499264
diff --git a/tools/gradle.py b/tools/gradle.py
index 1945557..64e6d51 100755
--- a/tools/gradle.py
+++ b/tools/gradle.py
@@ -14,7 +14,10 @@
 
 GRADLE_DIR = os.path.join(utils.REPO_ROOT, 'third_party', 'gradle')
 GRADLE_SHA1 = os.path.join(GRADLE_DIR, 'gradle.tar.gz.sha1')
-GRADLE = os.path.join(GRADLE_DIR, 'gradle', 'bin', 'gradle')
+if os.name == 'nt':
+  GRADLE = os.path.join(GRADLE_DIR, 'gradle', 'bin', 'gradle.bat')
+else:
+  GRADLE = os.path.join(GRADLE_DIR, 'gradle', 'bin', 'gradle')
 
 def PrintCmd(s):
   if type(s) is list:
diff --git a/tools/test.bat b/tools/test.bat
new file mode 100644
index 0000000..a343096
--- /dev/null
+++ b/tools/test.bat
@@ -0,0 +1,9 @@
+@echo off
+:: Copyright (c) 2017, the R8 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.
+setlocal
+
+PATH=%~dp0;%PATH%
+
+python "%~dp0\test.py" %*
\ No newline at end of file