Correct typos as per GH 20435

In GH 20435 many typos in our C code were corrected.  However, this pull
request was not applied to blead and developed merge conflicts.  I
extracted diffs for the individual modified files and applied them with
'git apply', excepting four files where patch conflicts were reported.
Those files were:

        handy.h
        locale.c
        regcomp.c
        toke.c

We can handle these in a subsequent commit. Also, had to run these two
programs to keep 'make test_porting' happy:

        $ ./perl -Ilib regen/uconfig_h.pl
        $ ./perl -Ilib regen/regcomp.pl regnodes.h

1 files changed, 1 insertions, 1 deletions

diff --git a/regcomp.h b/regcomp.h
index 306c732b75..d1a72ed24c 100644
--- a/regcomp.h
+++ b/regcomp.h
@@ -1329,7 +1329,7 @@ re.pm, especially to the documentation.
                      /* get_sv() can return NULL during global destruction. */ \
         re_debug_flags_sv = PL_curcop ? get_sv(RE_DEBUG_FLAGS, GV_ADD) : NULL; \
         if (re_debug_flags_sv) {                                               \
-            if (!SvIOK(re_debug_flags_sv)) /* If doesnt exist set to default */\
+            if (!SvIOK(re_debug_flags_sv)) /* If doesn't exist set to default */\
                 sv_setuv(re_debug_flags_sv,                                    \
                         /* These defaults should be kept in sync with re.pm */ \
                             RE_DEBUG_COMPILE_DUMP | RE_DEBUG_EXECUTE_MASK );   \