cleanup of parsing error reporting

[Doug Evans <dje at sebabeach dot org>]

Hi.

This patch is a follow-up to
http://sourceware.org/ml/cgen/2009-q3/msg00049.html

The old "errtxt" argument of the parsing routines has been replaced
with a <context> object, and everything now consistently uses it.
Gone are several fixmes too.

Tested by regenerating binutils, sid, intrinsics, and doc files.

2009-08-12  Doug Evans  <dje@sebabeach.org>

	Clean up cpu file parsing, pass context consistently instead of the
	old "errtxt" argument.
	NOTE: ACU == "All Callers Updated".
	* attr.scm (-parse-simple-attribute): Renamed from
	parse-simple-attribute, ACU.
	(-attr-parse): Change errtxt argument to context, ACU.
	(-attr-read): Ditto.
	(atlist-parse): Ditto.  Put context arg first.
	(attr-parse): Use parse-error instead of context-error.
	* enum.scm (parse-enum-vals): Change errtxt argument to context, ACU.
	(-enum-parse-prefix, -enum-parse, -enum-read): Ditto.
	* hardware.scm (-keyword-parse): Renamed from keyword-parse.
	`context' arg is now a <context> object.  ACU.
	(-keyword-read): `context' arg is now a <context> object.  ACU.
	(-hw-parse-indices): Change errtxt argument to context, ACU.
	(-hw-parse-values, -hw-parse-handlers): Ditto.
	(-hw-parse-getter, -hw-parse-setter, -hw-parse, -hw-read): Ditto.
	(-hw-validate-layout, -hw-create-getter-from-layout,
	-hw-create-setter-from-layout): Ditto.
	(<hw-register>:parse!, <hw-pc>:parse!): Ditto.
	(<hw-memory>:parse!, <hw-immediate>:parse!): Ditto.
	(<hw-address>:parse!): Ditto.
	* ifield.scm (-ifield-parse, ifield-read): Ditto.
	(-ifld-parse-follows, -ifld-parse-encode-decode): Ditto.
	(-ifld-parse-encode, -ifld-parse-decode): Ditto.
	(-multi-ifield-parse, -multi-ifield-read): Ditto.
	* insn.scm (-insn-parse, -insn-read): Ditto.
	(parse-syntax): Ditto.  Put context arg first.
	(-parse-insn-format-symbol): Change errtxt argument to context, ACU.
	(-parse-insn-format-ifield-spec, -parse-insn-format-list): Ditto.
	(-parse-insn-format): Ditto.
	* mach.scm (-arch-parse-alignment, -arch-parse-machs): Ditto.
	(-arch-parse-isas): Ditto.
	(-isa-read): Add context arg, ACU.
	(-cpu-parse, -cpu-read, -mach-read): Ditto.
	* minsn.scm (-minsn-parse-expansion): Change errtxt argument to
	context, ACU.
	(-minsn-parse, -minsn-read, -minsn-compute-iflds): Ditto.
	(minsn-make-alias): Ditto.
	* mode.scm (-mode-parse): Ditto.
	(parse-mode-name): Ditto.  Put context arg first.
	* model.scm (-prefetch-parse, -retire-parse, -pipeline-parse): Change
	errtxt argument to context, ACU.
	(-unit-parse, -model-parse, -model-read): Ditto.
	* operand.scm (-operand-parse-getter): Use parse-error instead of
	context-error.
	(-operand-parse-setter): Ditto.
	(-operand-parse): Change errtxt argument to context, ACU.
	(-operand-read, -derived-operand-parse, -derived-operand-read): Ditto.
	(-anyof-operand-parse, -anyof-operand-read): Ditto.
	* read.scm (reader-error): Delete.  Use parse-error instead.
	(parse-error): Change errtxt argument to context, ACU.  Split args
	argument into expr and maybe-help-text.
	(-reader-process-expanded-1!): Reorganize.
	* rtl.scm (-subr-read): Change errtxt argument to context, ACU.
	* types.scm (parse-type): Ditto.
	* utils-cgen.scm (single-location->simple-string): New function.
	(<context>): Replace members file,lineno with location.
	(make-prefix-context): Renamed from context-make-prefix, ACU.
	(make-current-context): New function.
	(context-append, context-append-name): New functions.
	(context-make-reader): Delete.
	(parse-name): Change errtxt argument to context, ACU.
	Put context arg first.
	(parse-comment): Ditto.
	(parse-number): Change errtxt argument to context, ACU.
	(arg-list-validate-name, arg-list-check-no-args,
	arg-list-symbol-arg): Ditto.