ninja windows: support and test for AdditionalIncludeDirectories

pylib/gyp/msvs_emulation.py

Index: pylib/gyp/msvs_emulation.py
diff --git a/pylib/gyp/msvs_emulation.py b/pylib/gyp/msvs_emulation.py
index 967c6d98eda79469e40f030b75c5414cd76322ff..081f14cda491281413a056eeda38c61c75f200da 100644
--- a/pylib/gyp/msvs_emulation.py
+++ b/pylib/gyp/msvs_emulation.py
@@ -244,7 +244,7 @@ class MsvsSettings(object):
       output_file = expand_special(self.ConvertVSMacros(output_file))
     return output_file
 
-  def GetCflags(self, config):
+  def GetCflags(self, config, gyp_to_build_path):
     """Returns the flags that need to be added to .c and .cc compilations."""
     cflags = []
     cflags.extend(['/wd' + w for w in self.msvs_disabled_warnings[config]])
@@ -268,6 +268,7 @@ class MsvsSettings(object):
     cl('RuntimeLibrary',
         map={'0': 'T', '1': 'Td', '2': 'D', '3': 'Dd'}, prefix='/M')
     cl('ExceptionHandling', map={'1': 'sc','2': 'a'}, prefix='/EH')
+    cl('AdditionalIncludeDirectories', prefix='/I', map=gyp_to_build_path)

[Nico, 2012/05/23 20:38:33]

I would've expected that in AdjustIncludeDirs, but I suppose it doesn't really
matter. A bit weird that there are now 3 places where includes can be added.

     cl('AdditionalOptions', prefix='')
     # ninja handles parallelism by itself, don't have the compiler do it too.
     cflags = filter(lambda x: not x.startswith('/MP'), cflags)