[lit] Check for the psutil module when setting a timeout

Apparently setting the per-test-timeout and not having the psutil
package constitutes to a fatal error. So only set the timeout when the
module is available.

llvm-svn: 359503

lldb/lit/lit.cfg.py

@@ -74,8 +74,14 @@ for i in ['module-cache-clang', 'module-cache-lldb']:
         print("Deleting module cache at %s."%cachedir)
         shutil.rmtree(cachedir)
 
-# Set a default  timeout of 10 minutes.
-lit_config.maxIndividualTestTime = 600
+# Set a default per-test timeout of 10 minutes. Setting a timeout per test
+# requires the psutil module and lit complains if the value is set but the
+# module can't be found.
+try:
+    import psutil  # noqa: F401
+    lit_config.maxIndividualTestTime = 600
+except ImportError:
+    pass
 
 # If running tests natively, check for CPU features needed for some tests.