Use bool where appropriate.

* lib/regcomp.c (re_set_fastmap): ICASE arg is bool, not int.
All callers changed.
(calc_eclosure_iter): Likewise, for ROOT arg.
(parse_bracket_element): Likewise, for ACCEPT_HYPHEN arg.
(build_charclass_op): Likewise, for NON_MATCH arg.
* lib/regex_internal.c (re_string_allocate, re_string_construct):
(re_string_construct_common): Likewise, for ICASE arg.
* lib/regexec.c (re_search_2_stub, re_search_stub):
Likewise, for RET_LEN arg.
(check_matching): Likewise, for FL_LONGEST_MATCH arg.
(set_regs): Likewise, for FL_BACKTRACK arg.
* lib/regcomp.c (re_compile_fastmap_iter, optimize_utf8):
(duplicate_node_closure, calc_inveclosure, calc_eclosure):
(calc_eclosure_iter, parse_bracket_exp):
Use bool for internal variables that are booleans.
* lib/regexec.c (re_search_internal, check_matching):
(proceed_next_node):
(set_regs, build_sifted_states, sift_states_bkref):
(check_arrival_add_next_nodes, check_arrival_expand_ecl_sub):
(expand_bkref_cache, build_trtable, group_nodes_into_DFAstates):
(find_collation_sequence_value):
Likewise.
* lib/regex_internal.c (re_node_set_insert, re_node_set_insert_last):
(re_node_set_compare):
Return bool, not int. All callers changed.
* lib/regexec.c (check_halt_node_context, check_dst_limits):
(build_trtable, check_node_accept): Likewise.
* lib/regex_internal.h: Include stdbool.h.

Fix bugs uncovered when converting to bool.
* lib/regcomp.c (calc_eclosure_iter): Check for storage allocation
failure instead of charging ahead blindly.
* lib/regex_internal.c (register_state): Likewise.
* lib/regexec.c (re_search_2_stub): Use simpler method than boolean
for freeing internal storage.
(group_nodes_into_DFA_states): Use unsigned int, not int, for
bitset pieces used as boolean, to avoid undefined behavior
on hosts that do int overflow checking.

* config/srclist.txt: Add glibc bug 1285.