[Bug other/100826] New: Add that "-fgcse-after-reload" is enabled at "-O3"

["firasuke at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100826

            Bug ID: 100826
           Summary: Add that "-fgcse-after-reload" is enabled at "-O3"
           Product: gcc
           Version: 11.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: other
          Assignee: unassigned at gcc dot gnu.org
          Reporter: firasuke at gmail dot com
  Target Milestone: ---

Hello there,

Upon reading the GCC manual I stumbled upon the following flag
`-fgcse-after-reload`, which happens to be mentioned twice, the first time
being at:

```
       -O3 Optimize yet more.  -O3 turns on all optimizations specified by -O2
and also turns on the following optimization flags:

           -fgcse-after-reload -fipa-cp-clone ...
```

and the second time:

```
       -fgcse-after-reload
           When -fgcse-after-reload is enabled, a redundant load elimination
pass is performed after reload.  The purpose of this pass is to clean up
redundant
           spilling.

           Enabled by -fprofile-use and -fauto-profile.
```

I think it'd be better if the following statement:

"Enabled by -fprofile-use and -fauto-profile."

be changed to:

"Enabled by -O3, -fprofile-use, and -fauto-profile."

to show that it is also enabled by `-O3`, similar to `-fpeel-loops`.

Thanks in advance!