Teach etags to process ENUM_BF correctly

Teach etags to process ENUM_BF correctly

* lib-src/etags.c (sym_type): New enumeration value st_C_enum_bf.
(hash): Regenerated values for asso_values[] array.
(in_word_set): Update values of TOTAL_KEYWORDS and
MAX_HASH_VALUE.  Add "ENUM_BF" to the wordlist[] array.
(in_enum_bf): New file-global variable.
(consider_token): Skip ENUM_BF if not in a macro definition.
(C_entries): Reset the in_enum_bf flag when past its closing
parenthesis.

* test/manual/etags/ETAGS.good_1:
* test/manual/etags/ETAGS.good_2:
* test/manual/etags/ETAGS.good_3:
* test/manual/etags/ETAGS.good_4:
* test/manual/etags/ETAGS.good_5:
* test/manual/etags/ETAGS.good_6:
* test/manual/etags/CTAGS.good: Adapt to changes in etags.