GN: Use gold linker for arm64

GN: Use gold linker for arm64

GN doesn't currently support adding an .a entry to libs (it won't not prefix it with -l). Easiest fix is to switch to gold linker, which supports using -l/path.a

BUG=568883

[agrieve, 2015-12-11 13:21:31]

Description was changed from

==========
GN: Fix arm64 libgcc.a linker flag

BUG=568883
==========

to

==========
GN: Fix arm64 libgcc.a linker flag

BUG=568883
==========

[agrieve, 2015-12-11 13:21:32]

agrieve@chromium.org changed reviewers:
+ yfriedman@chromium.org

[agrieve, 2015-12-11 13:21:37]

On 2015/12/11 13:21:32, agrieve wrote:
> mailto:agrieve@chromium.org changed reviewers:
> + mailto:yfriedman@chromium.org

◐ o ◑

[agrieve, 2015-12-11 14:59:06]

On 2015/12/11 13:21:37, agrieve wrote:
> On 2015/12/11 13:21:32, agrieve wrote:
> > mailto:agrieve@chromium.org changed reviewers:
> > + mailto:yfriedman@chromium.org
> 
> ◐ o ◑

Looks like this didn't actually work as I had thought and just triggers errors
further along. The flag needs to come closer to the end of the command line

[agrieve, 2015-12-11 16:22:16]

Description was changed from

==========
GN: Fix arm64 libgcc.a linker flag

BUG=568883
==========

to

==========
GN: Use gold linker for arm64

GN doesn't currently support adding an .a entry to libs (it won't not prefix it
with -l). Easiest fix is to switch to gold linker, which supports using
-l/path.a

BUG=568883
==========

[agrieve, 2015-12-11 16:22:57]

On 2015/12/11 14:59:06, agrieve wrote:
> On 2015/12/11 13:21:37, agrieve wrote:
> > On 2015/12/11 13:21:32, agrieve wrote:
> > > mailto:agrieve@chromium.org changed reviewers:
> > > + mailto:yfriedman@chromium.org
> > 
> > ◐ o ◑
> 
> Looks like this didn't actually work as I had thought and just triggers errors
> further along. The flag needs to come closer to the end of the command line

Switched this to using gold linker. Let's wait a bit and see if anyone knows
that it's a bad idea though.

[Yaron, 2015-12-11 16:24:58]

does gyp use gold for arm64?

[agrieve, 2015-12-11 17:26:06]

On 2015/12/11 16:24:58, Yaron wrote:
> does gyp use gold for arm64?

pasko pointed out that we shouldn't switch yet due to some arm errata. :/

[agrieve, 2015-12-11 17:51:57]

On 2015/12/11 17:26:06, agrieve wrote:
> On 2015/12/11 16:24:58, Yaron wrote:
> > does gyp use gold for arm64?
> 
> pasko pointed out that we shouldn't switch yet due to some arm errata. :/

Spoke with torne@ about this and looks like the answer is that I'll need to
teach GN how to pass libs without -l