Add a ${pathsep} variable to lit that expands to : (or ; on win32).

This is in braces so that it doesn't conflict with the existing %p.
It uses braces instead of parens because parens would have to be
regex-escaped.

llvm-svn: 153213

utils/lit/lit/TestRunner.py

@@ -471,6 +471,7 @@ def parseIntegratedTestScript(test, normalize_slashes=False,
     substitutions.extend([('%s', sourcepath),
                           ('%S', sourcedir),
                           ('%p', sourcedir),
+                          ('%{pathsep}', os.pathsep),
                           ('%t', tmpBase + '.tmp'),
                           ('%T', tmpDir),
                           # FIXME: Remove this once we kill DejaGNU.