Improve generated Makefile rules for rules with 2 outputs.

Improve generated Makefile rules for rules several outputs.

This layers a hack upon a hack, but it should strictly improve things and the code isn't too ugly.

What it does:
- If a rule has (exactly) 2 outputs, this will now generate
  out1 out2: file.intermediate
  .INTERMEDIATE: file.intermediate
  file.intermediate: deps
    command
- Previously, it would generate:
  out1: deps
    command
  out2: out1
  out2: ;

Why:
The old rule fails if someone removes out2 from the build tree and you
try to rebuild. People actually do that.

R=jochen@chromium.org
BUG=

Committed: https://chromium.googlesource.com/external/gyp/+/2a5511bd901f328db10d0b6415c864a5ff59fc81

[jochen (gone - plz use gerrit), 2015-04-07 17:00:41]

can you add a test for this please?

[vogelheim, 2015-04-08 15:02:43]

The existing tests relied on the number of executions for a rule and thus
couldn't deal with the occasional double execution. So I went for a different
approach.

Also added a test specifically for this scenario.

[vogelheim, 2015-04-08 15:08:39]

On 2015/04/08 15:02:43, vogelheim wrote:
> The existing tests relied on the number of executions for a rule and thus
> couldn't deal with the occasional double execution. So I went for a different
> approach.
> 
> Also added a test specifically for this scenario.

Err... no yet ready. There's still some issues. :(

[vogelheim, 2015-04-08 16:35:36]

Patchset #6 (id:100001) has been deleted

[vogelheim, 2015-04-08 16:39:41]

Patchset #6 (id:120001) has been deleted

[vogelheim, 2015-04-08 16:56:39]

Patchset #6 (id:140001) has been deleted

[vogelheim, 2015-04-08 16:56:52]

Patchset #6 (id:160001) has been deleted

[vogelheim, 2015-04-08 16:58:09]

On 2015/04/08 15:08:39, vogelheim wrote:
> On 2015/04/08 15:02:43, vogelheim wrote:
> > The existing tests relied on the number of executions for a rule and thus
> > couldn't deal with the occasional double execution. So I went for a
different
> > approach.
> > 
> > Also added a test specifically for this scenario.
> 
> Err... no yet ready. There's still some issues. :(

PTAL.

The trybots can't seem to apply the patch. I'm not sure how I can help them...
:(

[jochen (gone - plz use gerrit), 2015-04-09 14:46:43]

lgtm

https://codereview.chromium.org/1066963002/diff/180001/test/actions-multiple-...
File test/actions-multiple-outputs/gyptest-multiple-outputs.py (right):

https://codereview.chromium.org/1066963002/diff/180001/test/actions-multiple-...
test/actions-multiple-outputs/gyptest-multiple-outputs.py:3: # Copyright (c)
2009 Google Inc. All rights reserved.
2015

[vogelheim, 2015-04-09 17:12:36]

https://codereview.chromium.org/1066963002/diff/180001/test/actions-multiple-...
File test/actions-multiple-outputs/gyptest-multiple-outputs.py (right):

https://codereview.chromium.org/1066963002/diff/180001/test/actions-multiple-...
test/actions-multiple-outputs/gyptest-multiple-outputs.py:3: # Copyright (c)
2009 Google Inc. All rights reserved.
On 2015/04/09 14:46:43, jochen wrote:
> 2015

Done.

[vogelheim, 2015-04-10 16:23:46]

The CQ bit was checked by vogelheim@chromium.org to run a CQ dry run

[vogelheim, 2015-04-10 16:23:46]

The patchset sent to the CQ was uploaded after l-g-t-m from jochen@chromium.org
Link to the patchset: https://codereview.chromium.org/1066963002/#ps220001
(title: ".")

[commit-bot: I haz the power, 2015-04-10 16:24:38]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-04-10 16:24:39]

Commit queue rejected this change because it did not recognize the base URL.
Please commit your change manually.

[vogelheim, 2015-04-10 16:26:25]

The CQ bit was checked by vogelheim@chromium.org to run a CQ dry run

[vogelheim, 2015-04-10 16:26:25]

The patchset sent to the CQ was uploaded after l-g-t-m from jochen@chromium.org
Link to the patchset: https://codereview.chromium.org/1066963002/#ps240001
(title: ".")

[commit-bot: I haz the power, 2015-04-10 16:29:40]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-04-10 16:29:42]

Commit queue rejected this change because it did not recognize the base URL.
Please commit your change manually.

[vogelheim, 2015-04-10 16:30:38]

Patchset #8 (id:220001) has been deleted

[vogelheim, 2015-04-10 16:30:43]

Patchset #8 (id:240001) has been deleted

[jochen (gone - plz use gerrit), 2015-04-14 12:21:25]

Committed patchset #8 (id:260001) manually as
2a5511bd901f328db10d0b6415c864a5ff59fc81 (presubmit successful).