tick in symbols: rename new prototype scan_word and provide a forwarder

[tonycoz]

The change in prototype of the non-API scan_word() function caused B::Hooks::Parser to fail to build.

Instead, rename scan_word() with the new prototype to scan_word2() and provide a scan_word() with the old signature.

The scan_word2() entry may be removed once tick in symbol becomes an error.

Fixes #21162

[leonerd]

Tiniest comment: It's common in e.g. Linux kernel, when adding new functions with more arguments, to use the number of arguments to name the function. So here it'd be scan_word6. Do we want to consider doing similar in this case?

[ilmari]

Tiniest comment: It's common in e.g. Linux kernel, when adding new functions with more arguments, to use the number of arguments to name the function. So here it'd be scan_word6. Do we want to consider doing similar in this case?

There's precedent for that in perl too:

~/src/perl (blead $)$ rg '^Perl_\w+\d+\(' proto.h |rg -vi 'utf8|latin1|[iu](8|16|32|64)'
Perl_csighandler1(int sig);
Perl_csighandler3(int sig, Siginfo_t *info, void *uap);
Perl_do_aexec5(pTHX_ SV *really, SV **mark, SV **sp, int fd, int do_report)
Perl_gv_efullname4(pTHX_ SV *sv, const GV *gv, const char *prefix, bool keepmain);
Perl_gv_fullname4(pTHX_ SV *sv, const GV *gv, const char *prefix, bool keepmain);
Perl_my_atof2(pTHX_ const char *orig, NV *value);
Perl_my_atof3(pTHX_ const char *orig, NV *value, const STRLEN len);
Perl_pregfree2(pTHX_ REGEXP *rx);
Perl_sighandler1(int sig)
Perl_sighandler3(int sig, Siginfo_t *info, void *uap)
Perl_sys_init3(int *argc, char ***argv, char ***env);
Perl_gv_efullname3(pTHX_ SV *sv, const GV *gv, const char *prefix);
Perl_gv_fullname3(pTHX_ SV *sv, const GV *gv, const char *prefix);
Perl_do_exec3(pTHX_ const char *incmd, int fd, int do_report)

[tonycoz]

Tiniest comment: It's common in e.g. Linux kernel, when adding new functions with more arguments, to use the number of arguments to name the function. So here it'd be scan_word6. Do we want to consider doing similar in this case?

Good idea, done.

[leonerd]

LGTM

As it's a BBC issue, do we want to consider putting this in before 5.38.0-RC2?

[ilmari]

As it's a BBC issue, do we want to consider putting this in before 5.38.0-RC2?

I thinks so, but I guess it's up to @rjbs to decide.