gcc bootstrap or such outdated references in src.conf and make.conf for 13 and 14

QUOTE from man src.conf :
 To be able to build the system, either gcc
             or clang bootstrap must be enabled unless an alternate compiler
             is provided via XCC.
END QUOTE

QUOTE from man src.conf :
The CCACHE_COMPILERCHECK
             option defaults to content when using the in-tree bootstrap
             compiler, and mtime when using an external compiler.  The
             CCACHE_CPP2 option is used for Clang but not GCC.
END QUOTE

With clang/clang++ 11's change to what -O means, I'm not sure about
the following from man make.conf :

QUOTE from man make.conf
     CFLAGS        (str) Controls the compiler setting when compiling C code.
                   Optimization levels other than -O and -O2 are not
                   supported.
END QUOTE

Same here:

QUOTE from man make.conf
     COPTFLAGS     (str) Controls the compiler settings when building the
                   kernel.  Optimization levels above [-O (-O2, ...)] are not
                   guaranteed to work.
END QUOTE


Context man outputs are from:

# ~/fbsd-based-on-what-freebsd-main.sh 
merge-base: 3f43ada98c89bce5ae416e203ba0e81595a5cd88
merge-base: CommitDate: 2021-01-29 19:46:24 +0000
e124d7d5fc88 (HEAD -> mm-src) mm-src snapshot for mm's patched build in git context.
3f43ada98c89 (freebsd/main, freebsd/HEAD, pure-src, main) Catch up with 6edfd179c86: mechanically rename IFCAP_NOMAP to IFCAP_MEXTPG.
FreeBSD FBSDFHUGE 14.0-CURRENT FreeBSD 14.0-CURRENT mm-src-n244523-e124d7d5fc88 GENERIC-NODBG  amd64 amd64 1400003 1400003


===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)