mmencode: implicit int errors

[amadeus24]

mmencode don't build on M1 Max, Seq. 15.2

:info:build codes.c:20:14: warning: a function declaration without a prototype is deprecated in all versions of C and is treated as a zero-parameter prototype in C2x, conflicting with a previous declaration [-Wdeprecated-non-prototype]
:info:build    20 | extern char *index();
:info:build       |              ^
:info:build codes.c:52:5: warning: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Wdeprecated-non-prototype]
:info:build    52 | int nextcharin(infile, PortableNewlines)
:info:build       |     ^
:info:build codes.c:76:1: warning: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Wdeprecated-non-prototype]
:info:build    76 | to64(infile, outfile, PortableNewlines) 
:info:build       | ^
:info:build codes.c:105:27: error: parameter 'pads' was not declared, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
:info:build   105 | output64chunk(c1, c2, c3, pads, outfile)
:info:build       |                           ^
:info:build   106 | FILE *outfile;
:info:build   107 | {
:info:build codes.c:105:23: error: parameter 'c3' was not declared, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
:info:build   105 | output64chunk(c1, c2, c3, pads, outfile)
:info:build       |                       ^
:info:build   106 | FILE *outfile;
:info:build   107 | {
:info:build codes.c:105:19: error: parameter 'c2' was not declared, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
:info:build   105 | output64chunk(c1, c2, c3, pads, outfile)
:info:build       |                   ^
:info:build   106 | FILE *outfile;
:info:build   107 | {
:info:build codes.c:105:15: error: parameter 'c1' was not declared, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
:info:build   105 | output64chunk(c1, c2, c3, pads, outfile)
:info:build       |               ^
:info:build   106 | FILE *outfile;
:info:build   107 | {
:info:build codes.c:105:1: warning: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Wdeprecated-non-prototype]
:info:build   105 | output64chunk(c1, c2, c3, pads, outfile)
:info:build       | ^
:info:build codes.c:122:1: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
:info:build   122 | PendingBoundary(s, Boundaries, BoundaryCt)
:info:build       | ^
:info:build       | int
:info:build codes.c:122:1: warning: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Wdeprecated-non-prototype]
:info:build codes.c:148:1: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
:info:build   148 | almostputc(c, outfile, PortableNewlines)
:info:build       | ^
:info:build       | int
:info:build codes.c:148:1: warning: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Wdeprecated-non-prototype]
:info:build codes.c:183:1: warning: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Wdeprecated-non-prototype]
:info:build   183 | from64(infile, outfile, boundaries, boundaryct, PortableNewlines) 
:info:build       | ^
:info:build codes.c:285:1: warning: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Wdeprecated-non-prototype]
:info:build   285 | toqp(infile, outfile) 
:info:build       | ^
:info:build codes.c:361:1: warning: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Wdeprecated-non-prototype]
:info:build   361 | fromqp(infile, outfile, boundaries, boundaryct) 
:info:build       | ^
:info:build 9 warnings and 6 errors generated.
:info:build mmencode.c:30:1: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
:info:build    30 | main(argc, argv)
:info:build       | ^
:info:build       | int
:info:build mmencode.c:30:1: warning: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Wdeprecated-non-prototype]
:info:build 1 warning and 1 error generated.
:info:build make: *** [codes.o] Error 1
:info:build make: *** Waiting for unfinished jobs....
:info:build make: *** [mmencode.o] Error 1
:info:build make: Leaving directory `/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_textproc_mmencode/mmencode/work/mm2.7/src/metamail'
:info:build Command failed:  cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_textproc_mmencode/mmencode/work/mm2.7/src/metamail" && /usr/bin/make -j10 -w mmencode CC="/usr/bin/clang -arch arm64" 
:info:build Exit code: 2
:error:build Failed to build mmencode: command execution failed
:debug:build Error code: CHILDSTATUS 32998 2
:debug:build Backtrace: command execution failed
:debug:build     while executing
:debug:build "system {*}$notty {*}$callback {*}$nice $fullcmdstring"
:debug:build     invoked from within
:debug:build "command_exec -callback portprogress::target_progress_callback build"
:debug:build     (procedure "portbuild::build_main" line 10)
:debug:build     invoked from within
:debug:build "$procedure $targetname"