[Bug gcov-profile/65372] New: -mprofile-kernel undocumented

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65372

            Bug ID: 65372
           Summary: -mprofile-kernel undocumented
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: gcov-profile
          Assignee: unassigned at gcc dot gnu.org
          Reporter: msebor at gcc dot gnu.org

The -mprofile-kernel option supported by GCC and documented in the output of
GCC --help -v is not documented in the GCC online or info manuals:

$ /build/gcc-trunk-git/gcc/xgcc -B/build/gcc-trunk-git/gcc --help -v 2>&1 |
grep -A1 kernel
  -mprofile-kernel            Call mcount for profiling before a function
                              prologue

The lack of more detailed documentation makes it difficult to reason about the
expected behavior in cases such as pr63354.