[gold][aarch64]Give informative error message when stub-group-size is too large

[Jing Yu <jingyu at google dot com>]

Hi Cary,

This patch gives informative error message when current stub is too
far away during relaxation. The old version only says "Stub is too far
away, try a smaller value for '--stub-group-size'. For example,
0x2000000." With the patch, user will know the current stub-group-size
value and therefore knows how to set the proper value.

OK for trunk?

Thanks,
Jing

gold/ChangeLog:

2014-12-10  Jing Yu  <jingyu@google.com>

      * aarch64.cc (Target_aarch64): Add new variable: stub_group_size_.
      (AArch64_relocate_functions::maybe_apply_stub): Add new parameter.
      Update error message.
      (Target_aarch64::do_relax): Use absolute value of option
stub_group_size. Replace local variable with class member
stub_group_size_.

Attachment: farstub.patch
Description: Binary data