ninja windows: VS2013 improvements

ninja windows: VS2013 improvements

- Use vs2013 x64->x86 cross compiler if available
- Add /FS compiler flag which maintains previous version PDB behavior.

R=thakis@chromium.org
BUG=chromium:288948
Committed: https://code.google.com/p/gyp/source/detail?r=1725

[Nico, 2013-09-12 17:23:21]

lgtm

https://codereview.chromium.org/23447022/diff/1/pylib/gyp/msvs_emulation.py
File pylib/gyp/msvs_emulation.py (right):

https://codereview.chromium.org/23447022/diff/1/pylib/gyp/msvs_emulation.py#n...
pylib/gyp/msvs_emulation.py:365: # New flag required in 2013 to maintain
previous PDB behavior.
What's the new behavior do?

[scottmg, 2013-09-12 17:29:10]

On 2013/09/12 17:23:21, Nico wrote:
> lgtm
> 
> https://codereview.chromium.org/23447022/diff/1/pylib/gyp/msvs_emulation.py
> File pylib/gyp/msvs_emulation.py (right):
> 
>
https://codereview.chromium.org/23447022/diff/1/pylib/gyp/msvs_emulation.py#n...
> pylib/gyp/msvs_emulation.py:365: # New flag required in 2013 to maintain
> previous PDB behavior.
> What's the new behavior do?

It writes pdbs directly from the compiler, rather than by using the mspdbsrv
daemon. Theoretically that sounds nice, but there's additional restrictions on
sharing pdbs (which we don't meet and so the compiler yells and errors out).

PDBs are mostly intended to deduplicate typeinfo across translation units, so it
seems like you lose most of their benefit too. It might be useful the new
behaviour in a distcc-like setup though.

[scottmg, 2013-09-12 18:35:39]

Committed patchset #1 manually as r1725.