More fixes for PNaCl Windows.

tools/llvm/driver/pathtools.py

 #!/usr/bin/python
 # Copyright (c) 2011 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
 # IMPORTANT NOTE: If you make local mods to this file, you must run:
 #   %  tools/llvm/utman.sh driver
 # in order for them to take effect in the scons build.  This command
 # updates the copy in the toolchain/ tree.
 #
@@ skipping 27 matching lines @@
 
 def normalize(syspath):
   """ Convert an input path into a normalized path. """
 
   if WINDOWS_MANGLE:
     # Recognize paths which are already normalized.
     # (Should only happen during recursive driver calls)
     if syspath.startswith('/cygdrive/'):
       return syspath
 
+    # Leave '-' alone since it represents stdout and not a real path.
+    if syspath == '-':
+      return syspath
+
     components = os.path.abspath(syspath).split('\\')
     drive = components[0]
     components = components[1:]
     assert(len(drive) == 2 and drive[1] == ':')
     return '/cygdrive/%s/%s' % (drive[0].lower(), '/'.join(components))
   else:
     return syspath
 
 # All functions below expect a normalized path as input
 
@@ skipping 41 matching lines @@
     return posixpath.abspath(npath)
 
 def isdir(npath):
   return os.path.isdir(tosys(npath))
 
 def isfile(npath):
   return os.path.isfile(tosys(npath))
 
 def getsize(npath):
   return os.path.getsize(tosys(npath))