[Bug other/82061] New: -Wall documentation needs updating

["wilson at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82061

            Bug ID: 82061
           Summary: -Wall documentation needs updating
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: other
          Assignee: unassigned at gcc dot gnu.org
          Reporter: wilson at gcc dot gnu.org
  Target Milestone: ---

I see multiple problems with the -Wall documentation.

There are generic options missing, such as -Wframe-address.  There are C++
specific options missing, such as -Wclass-memaccess.  There are C++ specific
options present, but not mentioned as C++ specific, such as -Wreorder.  The
*.opt files need to be checked to see if there are other similar issues.

There are multiple ways to specify that an option is language dependent, e.g.
only for X, only in X, X only, in X.  This is inconsistent, we should probably
choose one and use it consistently.