Use no_strict_aliasing=1 by default.

Use no_strict_aliasing=1 by default.

This will turn on -fno-strict-aliasing. There are regular aliasing problems
in the codebase and at least one of these was not caught by -Wall -Werror
so defaulting to -fno-strict-aliasing seems like a good idea especially
given the increased popularity of gcc 4.4 with it's use in karmic, fedora and in
chromeos chroot builds et. al.

The long term plan is to have some test infrastructure in place that will test
4.4 binaries and to fix the aliasing issues.

BUG=28749
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=36151

[Evan Martin, 2010-01-13 18:01:23]

http://codereview.chromium.org/519034/diff/1/2
File build/common.gypi (right):

http://codereview.chromium.org/519034/diff/1/2#newcode585
build/common.gypi:585: {'no_strict_aliasing%': 0,},],
Maybe we should just default the variable to 1, regardless of the compiler? 
That would make it more explicit on gcc 4.3 too..

[Craig, 2010-01-13 18:27:16]

On 2010/01/13 18:01:23, Evan Martin wrote:
> http://codereview.chromium.org/519034/diff/1/2
> File build/common.gypi (right):
> 
> http://codereview.chromium.org/519034/diff/1/2#newcode585
> build/common.gypi:585: {'no_strict_aliasing%': 0,},],
> Maybe we should just default the variable to 1, regardless of the compiler? 
> That would make it more explicit on gcc 4.3 too..

Defaulted to 1 now and put in some explanatory waffling and updated the
description. I'll file a bug or two later to sort this out properly.

[Evan Martin, 2010-01-13 18:29:57]

LGTM