lit: Propagate TERM variable in environment, some tools can do really obscure

odd things if this is missing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166289 91177308-0d34-0410-b5e6-96231b3b80d8

utils/lit/lit/TestingConfig.py

@@ -16,6 +16,7 @@ class TestingConfig:
                 'PATH' : os.pathsep.join(litConfig.path +
                                          [os.environ.get('PATH','')]),
                 'SYSTEMROOT' : os.environ.get('SYSTEMROOT',''),
+                'TERM' : os.environ.get('TERM',''),
                 'LLVM_DISABLE_CRASH_REPORT' : '1',
                 }