Move gdb_regex* to common/

Move gdb_regex* to common/

Later patches need regex support also in gdbserver.

gdb/ChangeLog
2015-07-15  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* Makefile.in (HFILES_NO_SRCDIR): Change gdb_regex.h to
	common/gdb_regex.h.
	(COMMON_OBS): Add gdb_regex.o.
	(gdb_regex.o): New.
	* common/common.m4 (GDB_AC_COMMON): Add gdb_use_included_regex,
	--without-included-regex and USE_INCLUDED_REGEX.
	* common/gdb_regex.c: New file from utils.c functions.
	* common/gdb_regex.h: Move it here from gdb_regex.h, update include
	file wrapping define name.
	* configure: Rebuilt.
	* configure.ac (gdb_use_included_regex, --without-included-regex)
	(USE_INCLUDED_REGEX): Move them to common/common.m4.
	* gdb_regex.h: Move it to common/gdb_regex.h.
	* utils.c: Remove include gdb_regex.h.
	(do_regfree_cleanup, make_regfree_cleanup, get_regcomp_error)
	(compile_rx_or_error): Move them to common/gdb_regex.c.

gdb/gdbserver/ChangeLog
2015-07-15  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* Makefile.in (OBS): Add gdb_regex.o.
	(gdb_regex.o): New.
	* config.in: Rebuilt.
	* configure: Rebuilt.