ninja: Pass .so files outside of --start-group/--end-group.

When doing 32bit release component builds of chromium, nacl_helper fails to
link like so:

g++ [...] -Wl,--as-needed -o nacl_helper -Wl,--start-group [...] obj/components/libnacl_linux.a [...] lib/libppapi_shared.so -Wl,--end-group [...]

  /usr/bin/ld: .../nacl_linux.plugin_main.o: undefined reference to symbol '_ZN5ppapi16PPB_Audio_Shared18SetThreadFunctionsEPK18PP_ThreadFunctions'
  /usr/bin/ld: note: '_ZN5ppapi16PPB_Audio_Shared18SetThreadFunctionsEPK18PP_ThreadFunctions' is defined in DSO lib/libppapi_shared.so so try adding it to the linker command line

Note that libppapi_shared.so is on the link line.  The error goes away if
--as-needed isn't passed, if I use gold, or if the .so file is moved after
--end-group.  http://wiki.gentoo.org/wiki/Project:Quality_Assurance/As-needed
suggests that --as-needed has additional constraints on library ordering, and
I'm guessing that this error depends on how the implementations of
--as-needed and --start-group/--end-group in ld.bfd interact.

Moving $solibs out of --start-group/--end-group seems to work, so just do that.
No test because we have no 32bit linux gyp bot.

BUG=none (but found while working on 368384 / 385472)
TEST=Build nacl_test on a 32bit release bot using the components build. links correctly
R=scottmg@chromium.org

Review URL: https://codereview.chromium.org/341613003

git-svn-id: http://gyp.googlecode.com/svn/trunk@1944 78cadc50-ecff-11dd-a971-7dbc132099af