extract/store integer function template

extract/store integer function template

This patch converts functions extract_{unsigned,signed}_integer
to a function template extract_integer, which has two instantiations.  It
also does the similar changes to store__{unsigned,signed}_integer,
regcache::raw_read_{unsigned,signed}, regcache::raw_write_{unsigned,signed},
regcache::cooked_read_{unsigned,signed},
regcache::cooked_write_{unsigned,signed}.

This patch was posted here
https://sourceware.org/ml/gdb-patches/2017-05/msg00492.html but the
problem was fixed in a different way.  However, I think the patch is still
useful to shorten the code.

gdb:

2017-06-16  Alan Hayward  <alan.hayward@arm.com>
	    Pedro Alves  <palves@redhat.com>
	    Yao Qi  <yao.qi@linaro.org>

	* defs.h (RequireLongest): New.
	(extract_integer): Declare function template.
	(extract_signed_integer): Remove the declaration, but define it
	static inline.
	(extract_unsigned_integer): Likewise.
	(store_integer): Declare function template.
	(store_signed_integer): Remove the declaration, but define it
	static inline.
	(store_unsigned_integer): Likewise.
	* findvar.c (extract_integer): New function template.
	(extract_signed_integer): Remove.
	(extract_unsigned_integer): Remove.
	(extract_integer<LONGEST>, extract_integer<ULONGEST>): Explicit
	instantiations.
	(store_integer): New function template.
	(store_signed_integer): Remove.
	(store_unsigned_integer): Remove.
	(store_integer): Explicit instantiations.
	* regcache.c (regcache_raw_read_signed): Update.
	(regcache::raw_read): New function.
	(regcache::raw_read_signed): Remove.
	(regcache::raw_read_unsigned): Remove.
	(regcache_raw_read_unsigned): Update.
	(regcache_raw_write_unsigned): Update.
	(regcache::raw_write_signed): Remove.
	(regcache::raw_write): New function.
	(regcache_cooked_read_signed): Update.
	(regcache::raw_write_unsigned): Remove.
	(regcache::cooked_read_signed): Remove.
	(regcache_cooked_read_unsigned): Update.
	(regcache::cooked_read_unsigned): Remove.
	(regcache_cooked_write_signed): Update.
	(regcache_cooked_write_unsigned): Update.
	* regcache.h (regcache) <raw_read_signed>: Remove.
	<raw_write_signed, raw_read_unsigned, raw_write_unsigned>: Remove.
	<raw_read, raw_write>: New.
	<cooked_read_signed, cooked_write_signed>: Remove.
	<cooked_write_unsigned, cooked_read_unsigned>: Remove.
	<cooked_read, cooked_write>: New.
	* sh64-tdep.c (sh64_pseudo_register_read): Update.
	(sh64_pseudo_register_write): Update.