[PATCH users/roland/ld-depfile] ld, gold: Add --dependency-file option.

[Fangrui Song]

* Alan Modra
>Oh, and please fix some whitespace errors.  Add this to your
>.git/config to see them.
>[core]
>	whitespace = indent-with-non-tab,space-before-tab,trailing-space

There probably should be a how-to-contribute page on
https://www.gnu.org/software/binutils/ and the tip should be mentioned there.

On 2020-06-23, Roland McGrath via Binutils wrote:
>On Tue, Jun 23, 2020 at 8:11 AM Alan Modra <amodra@gmail.com> wrote:
>> [...] So, I'll OK the ld.bfd part of the patch if you'll
>> own any bug reports on this ld feature.
>
>Fair enough.
>
>You indicated earlier there were input files that my change did not
>include in dependency output.  If you think that's so, please point
>them out to me.
>
>> Oh, and please fix some whitespace errors.
>
>Thanks for noticing.  I try to be conscientious about those but it's
>always hard juggling the contrary requirements of various different
>projects.
>
>Committed to trunk.
>
>
>Thanks,
>Roland

--- a/ld/lexsup.c
+++ b/ld/lexsup.c
@@ -111,6 +111,8 @@ static const struct ld_option ld_options[] =
      'c', N_("FILE"), N_("Read MRI format linker script"), TWO_DASHES },
    { {"dc", no_argument, NULL, 'd'},
      'd', NULL, N_("Force common symbols to be defined"), ONE_DASH },
+  { {"dependency-file", required_argument, NULL, OPTION_DEPENDENCY_FILE},
+    '\0', N_("FILE"), N_("Write dependency file"), TWO_DASHES },

Should have used EXACTLY_TWO_DASHES for newer options to avoid clash with short options.

gold/fileread.h gold/layout.cc gold/options.h ld/lexsup.c ld/ldmain.c and several other files
have formatting changes which should have been committed separately.