[lit] Disable shtest-timeout on Windows

[stella.stamenova]

Summary

This is the only test that is still failing on Windows - or rather, it is expected to fail on the bots, but passes on the new bot that we're preparing causing a failure, so I'm going to disable it. Since the test has rarely, if ever, passed on the bots, this should have the same effect and it will unblock the creation of the new bot.

[zturner]

Lgtm

llvm/trunk/utils/lit/tests/Inputs/shtest-timeout/lit.cfg

 # -*- Python -*-
 import os
 import sys
 
 import lit.formats
 
 config.name = 'per_test_timeout'
 
 shellType = lit_config.params.get('external', '1')
 
 if shellType == '0':
     lit_config.note('Using internal shell')
     externalShell = False
 else:
     lit_config.note('Using external shell')
-    externalShell = (not sys.platform in ['win32'])
-    if not externalShell:
-        lit_config.note('External shell requested, but using internal shell')
+    externalShell = True
 
 configSetTimeout = lit_config.params.get('set_timeout', '0')
 
 if configSetTimeout != '0':
     # Try setting the max individual test time in the configuration
     lit_config.maxIndividualTestTime = int(configSetTimeout)
 
 config.test_format = lit.formats.ShTest(execute_external=externalShell)
 config.suffixes = ['.py']
 
 config.test_source_root = os.path.dirname(__file__)
 config.test_exec_root = config.test_source_root
 config.target_triple = '(unused)'
 src_root = os.path.join(config.test_source_root, '..')
 config.environment['PYTHONPATH'] = src_root
 config.substitutions.append(('%{python}', '"%s"' % (sys.executable)))

llvm/trunk/utils/lit/tests/shtest-timeout.py

 # REQUIRES: python-psutil
 
-# PR33944
-# XFAIL: windows
+# llvm.org/PR33944
+# REQUIRES: nowindows
 
 # FIXME: This test is fragile because it relies on time which can
 # be affected by system performance. In particular we are currently
 # assuming that `short.py` can be successfully executed within 2
 # seconds of wallclock time.
 
 # Test per test timeout using external shell
 # RUN: not %{lit} \