Only build the x86 arches we actually need.

Only build the x86 arches we actually need.

BUG=https://code.google.com/p/chromium/issues/detail?id=388101
TEST=trybots

[binji, 2014-07-02 18:49:10]

looks good in general, though I'd want to make sure that the NaCl SDK build
still works with these changes.

https://codereview.chromium.org/366763003/diff/120001/build/untrusted.gypi
File build/untrusted.gypi (right):

https://codereview.chromium.org/366763003/diff/120001/build/untrusted.gypi#ne...
build/untrusted.gypi:371: # x86-64 newlib nexe action
bad comment

[Mark Seaborn, 2014-07-02 18:58:30]

Please fill out BUG= https://code.google.com/p/chromium/issues/detail?id=388101

[jam, 2014-07-02 20:49:19]

Thanks for working on this.

Mac is still 32 bit though, so don't we also need the other way around of only
building 64 bit there if we're building 64 bit mac?

Also, perhaps not part of this cl, but on the trybots we build and test on the
same architecture, so building 32 & 64 bit IRTs on Windows is not necessary. Can
the trybots set special GYP flag to disable 32 bit IRT generation?

[jam, 2014-07-22 17:12:02]

ping?

[Mark Seaborn, 2014-07-22 17:40:27]

"TEST=trybots" is not really enough testing.  Can you do Chromium trybot runs
for this change, using clobber builds, please?

https://codereview.chromium.org/366763003/diff/120001/build/untrusted.gypi
File build/untrusted.gypi (right):

https://codereview.chromium.org/366763003/diff/120001/build/untrusted.gypi#ne...
build/untrusted.gypi:369: ['target_arch=="ia32" or (target_arch=="x64" and
OS=="win")', {
64-bit Windows Chrome builds don't need to include x86-32 nexes, AFAIK.

https://codereview.chromium.org/366763003/diff/120001/build/untrusted.gypi#ne...
build/untrusted.gypi:1566: ['target_arch=="ia32" or target_arch=="x64"', {
What about this one?

To avoid duplication, can we define some "build for x86_32" and "build for
x86_64" variables in a single place?