[patch] Use a std::vector instead of a std::map to hold Input_merge_map

[Sriraman Tallam]

Some minor changes:

+  const Section_merge_maps &maps = this->section_merge_maps_;
+  for (Section_merge_maps::const_iterator i = maps.begin(), e =maps.end();
+       i != e; ++i) {

space between '=' and maps.end()
'{' should come in a new line?

Otherwise patch makes the code simpler and looks good to me.  I do not
have the authority to approve.

Thanks
Sri

On Wed, May 20, 2015 at 6:12 AM, Rafael Espíndola
<rafael.espindola@gmail.com> wrote:
> ping
>
> On 23 April 2015 at 12:36, Rafael Espíndola <rafael.espindola@gmail.com> wrote:
>> A std::map is hardly the best data structure for a small map from
>> small integers.
>>
>> The attached patch uses a std::vector<std::pair>> instead.
>>
>> This simplifies the code and speeds up linking of chromium (see
>> attached perf logs).
>>
>> Cheers,
>> Rafael
>>
>> 2015-04-23  Rafael Ávila de Espíndola <rafael.espindola@gmail.com>
>>
>> * merge.cc (get_input_merge_map): Update for data structure change.
>> (get_or_make_input_merge_map): Update for data structure change.
>> * merge.h (Object_merge_map): Use a std::vector<std::pair>> instead of
>> a std::map.