lit: Pass %INCLUDE% to tests on Win32. clang may expect existence of %INCLUDE% in vcvarsall.bat.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152588 91177308-0d34-0410-b5e6-96231b3b80d8

utils/lit/lit/TestingConfig.py

@@ -21,6 +21,7 @@ class TestingConfig:
 
             if sys.platform == 'win32':
                 environment.update({
+                        'INCLUDE' : os.environ.get('INCLUDE',''),
                         'PATHEXT' : os.environ.get('PATHEXT',''),
                         'PYTHONUNBUFFERED' : '1',
                         'TEMP' : os.environ.get('TEMP',''),