Fix rpath for components when cross-compiling.

Fix rpath for components when cross-compiling.

This came up while bringing up the components build for Android. Trying
to run v8_shell failed: out/Debug/v8_shell: error while loading shared
libraries: libv8.cr.so: cannot open shared object file: No such file or
directory

readelf -d out/Debug/v8_shell

shows the problem:
 0x0000000f (RPATH)                      Library rpath: [$ORIGIN/lib/]

For cross-compiles, host shared libraries are placed in /lib/host

BUG=chromium:158821
Committed: https://code.google.com/p/gyp/source/detail?r=1607

[Nico, 2013-04-10 23:33:41]

Is it possible to write a test for this? I think we have toolset tests somewhere
below test/

[Yaron, 2013-04-11 05:50:31]

Added a test but it fails on mac/win. I think mac needs a similar fix in
xcode_emulation

Not sure what to make of win: 'ar' is not recognized as an internal or external
command,

[Nico, 2013-04-11 06:26:51]

Thanks for adding a test!

As far as I know, GYP_CROSSCOMPILE and the target / host stuff is only expected
to work on linux, so I think it's fine to make the new test linux-only.

[Yaron, 2013-04-11 16:51:53]

Ok, restricted to linux-only

[Nico, 2013-04-11 17:55:57]

lgtm

Thanks!

[Yaron, 2013-04-11 18:11:21]

I get this when trying to dcommit:

ERROR from SVN:
RA layer request failed: Server sent unexpected return value (405 Method Not
Allowed) in response to MKACTIVITY request for
'/svn/!svn/act/13f340d3-775a-4827-ac40-2d2549a510fd'
ERROR: Not all changes have been committed into SVN.
Please see the above messages for details.

I assume I don't have committer access to gyp?

[Yaron, 2013-04-11 18:28:57]

Committed patchset #3 manually as r1607 (presubmit successful).