opth-gen.awk: Generate mapping from cpp message reasons to the options that enable...

opth-gen.awk: Generate mapping from cpp message reasons to the options that enable them.

gcc/ChangeLog:

2014-09-09  Manuel López-Ibáñez  <manu@gcc.gnu.org>

	* opth-gen.awk: Generate mapping from cpp message reasons to the
	options that enable them.
	* doc/options.texi (CppReason): Document.

gcc/c-family/ChangeLog:

2014-09-09  Manuel López-Ibáñez  <manu@gcc.gnu.org>

	* c.opt: Add CppReason to various flags.
	(Wdate-time): Re-sort.
	* c-common.c: Include c-common.h earlier.
	(struct reason_option_codes_t): Delete.
	(c_option_controlling_cpp_error): Prefix global type and struct
	with cpp_.

From-SVN: r215095