probe: Replace VEC(probe_ops_cp) with std::vector

probe: Replace VEC(probe_ops_cp) with std::vector

This patch replaces the usage of VEC to store pointers to probe_ops with
an std::vector.  The sole usage of that vector type is one global
variable that holds the ops for the various kinds of probes, so this is
pretty straightforward (no allocation/deallocation issues).

gdb/ChangeLog:

	* probe.h (probe_ops_cp): Remove typedef.
	(DEF_VEC_P (probe_ops_cp)): Remove.
	(all_probe_ops): Change type to std::vector.
	* probe.c (info_probes_for_ops): Adjust to vector change.
	(probe_linespec_to_ops): Likewise.
	(all_probe_ops): Change type to std::vector.
	(_initialize_probe): Adjust to vector change.
	* dtrace-probe.c (_initialize_dtrace_probe): Likewise.
	* elfread.c (elf_get_probes): Likewise.
	* stap-probe.c (_initialize_stap_probe): Likewise.