PR23691, gas .y files vs. automatic make dependencies

PR23691, gas .y files vs. automatic make dependencies

A number of targets, bfin, rl78, rx, can show odd failures when
bfd/reloc.c changes BFD_RELOC_* enum values, if recompiling over a
build dir with existing objects.  The problem is caused by
bfin-parse.o and similar not being recompiled and so using stale
BFD_RELOC_* values.  This isn't fixed by making bfin-parse.c depend on
bfd/reloc.c, which isn't necessary anyway.  bfin-parse.o should have
been recompiled due to bfd/bfd.h changing when extracted bfd/reloc.c
BFD_RELOC_* values change, but that wasn't happening.  The problem is
that automake generates a makefile that loads gas/config/.deps/
dependency file for objects with corresponding sources mentioned in
EXTRA_as_new_SOURCES.  Unless we want to mess around generating
explicit dependencies, I think that mean moving some object files to
the build gas/config/.  This patch does that, removing some hacks for
m68k-parse.c that should no longer be necessary, and removes some
rules that catered to old bison producing code that triggers compiler
warnings.

	PR 23691
	* Makefile.am (TARGET_CPU_CFILES): Split off config/xtensa-relax.c..
	(TARGET_CPU_HFILES): ..and config/xtensa-relax.h..
	(TARGET_EXTRA_FILES): ..to here.  Add config/bfin-lex-wrapper.c,
	and use alongside TARGET_CPU_CFILES.
	(EXTRA_DIST): Update location of generated .c files.
	(config/m68k-parse.c): New rule replacing m68k-parse.c rule.
	(config/bfin-parse.c, config/rl78-parse.cm config/rx-parse.c),
	(config/bfin-lex.c, config/bfin-lex-wrapper.@OBJEXT@): Similarly.
	(itbl-lex-wrapper.@OBJEXT@): Simplify to just the needed
	dependencies.
	(itbl-parse.@OBJEXT@): Delete rule using NO_WERROR.
	(itbl-parse.c, itbl-parse.h): Tidy.
	* config/bfin-lex-wrapper.c: Include config/bfin-lex.c.
	* config/bfin-lex.l: Include config/bfin-parse.h.
	* configure.ac (extra_objects): Move object files corresponding
	to .y and .l files now in config/ to config/.
	* Makefile.in: Regenerate.
	* configure: Regenerate.
	* po/POTFILES.in: Regenerate.