[Bug c/79011] New: incorrect form of warning options listed in the manual

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79011

            Bug ID: 79011
           Summary: incorrect form of warning options listed in the manual
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: msebor at gcc dot gnu.org
  Target Milestone: ---

Section 3.8 of the manual, Options to Request or Suppress Warnings, states
that:

  "This manual lists only one of the two forms, whichever is not the default."

The following is a list of options listed in that section that, according to
the manual, are enabled by default (and thus should be listed in the -Wno-xxx
form).

-Wignored-attributes
-Wshift-count-negative
-Wshift-count-overflow
-Wshift-overflow (in C99 and later)
-Wswitch-unreachable
-Winvalid-memory-model
-Wstringop-overflow=2
-Wplacement-new
-Wpointer-compare
-Wno-endif-labels
-Wwrite-strings (in C++)
-Wsubobject-linkage
-Wdate-time
-Wenum-compare (in C++)
-Wsizeof-array-argument
-Wnormalized
-Woverride-init-side-effects
-Wpacked-bitfield-compat
-Wvarargs