ninja windows: fix mapping of optimization flags

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 7d37611fc2d397f30d1e9a4ee270675bd1ce4b92..a035451e7b672ca1caaf2fb087bb4a75d58c0af0 100644
--- a/pylib/gyp/msvs_emulation.py
+++ b/pylib/gyp/msvs_emulation.py
@@ -250,10 +250,11 @@ class MsvsSettings(object):
     cflags.extend(['/wd' + w for w in self.msvs_disabled_warnings[config]])
     cl = self._GetWrapper(self, self.msvs_settings[config],
                           'VCCLCompilerTool', append=cflags)
-    cl('Optimization', map={'0': 'd', '2': 's'}, prefix='/O')
+    cl('Optimization',
+       map={'0': 'd', '1': '1', '2': '2', '3': 'x'}, prefix='/O')
     cl('InlineFunctionExpansion', prefix='/Ob')
     cl('OmitFramePointers', map={'false': '-', 'true': ''}, prefix='/Oy')
-    cl('FavorSizeOrSpeed', map={'1': 's', '2': 't'}, prefix='/O')
+    cl('FavorSizeOrSpeed', map={'1': 't', '2': 's'}, prefix='/O')
     cl('WholeProgramOptimization', map={'true': '/GL'})
     cl('WarningLevel', prefix='/W')
     cl('WarnAsError', map={'true': '/WX'})