Adding a fix-it hint to a diagnostic usually follows one of these
patterns:
(a) an insertion fix-its, with the insertion at the primary caret location
(b) a removals/replacements, affecting the range of the primary location

(other cases are possible, e.g. multiple fix-its, and affecting other
locations, but these are the common ones)

Given these common cases, this patch adds overloads of the rich_location
methods for adding fix-it hints, so that the location information can
be omitted if it matches that of the primary location within the
rich_location.

Similarly when adding "remove" and "replace" fix-it hints to a diagnostic,
it's tedious to have to extract the source_range from a location_t
(aka source_location).  To make this more convenient, this patch
adds overload of the rich_location::add_fixit_remove/replace methods,
accepting a source_location directly.

The patch updates the various in-tree users of fix-it hints to use
the new simpler API where appropriate.  I didn't touch the case where
there are multiple fix-its in one rich_location, as it seems better to
be more explicit about locations for this case (adding a pair of parens
in warn_logical_not_parentheses).

The above makes the gcc_rich_location::add_fixit_misspelled_id overload
taking a const char * rather redundant, so I eliminated it.

gcc/c/ChangeLog:
	* c-decl.c (implicit_decl_warning): Use add_fixit_replace
	rather than add_fixit_misspelled_id.
	(undeclared_variable): Likewise.
	* c-parser.c (c_parser_declaration_or_fndef): Likewise.  Remove
	now-redundant "here" params from add_fixit_insert method calls.
	(c_parser_parameter_declaration): Likewise.
	* c-typeck.c (build_component_ref): Remove now-redundant range
	param from add_fixit_replace method calls.

gcc/cp/ChangeLog:
	* name-lookup.c (suggest_alternatives_for): Use add_fixit_replace
	rather than add_fixit_misspelled_id.
	* parser.c (cp_parser_diagnose_invalid_type_name): Likewise.

gcc/ChangeLog:
	* diagnostic-show-locus.c (test_one_liner_fixit_insert): Remove
	redundant location param.
	(test_one_liner_fixit_remove): Likewise.
	(test_one_liner_fixit_replace): Likewise.
	(test_one_liner_fixit_replace_equal_secondary_range): Likewise.
	* gcc-rich-location.c
	(gcc_rich_location::add_fixit_misspelled_id): Eliminate call to
	get_range_from_loc.  Drop overload taking a const char *.
	* gcc-rich-location.h
	(gcc_rich_location::add_fixit_misspelled_id): Drop overload taking
	a const char *.

libcpp/ChangeLog:
	* include/line-map.h (rich_location::add_fixit_insert): Add
	comments.  Add overload omitting the source_location param.
	(rich_location::add_fixit_remove): Add comments.  Add overloads
	omitting the range, and accepting a source_location.
	(rich_location::add_fixit_replace): Likewise.
	* line-map.c (rich_location::add_fixit_insert): Add comments.  Add
	overload omitting the source_location param.
	(rich_location::add_fixit_remove): Add comments.  Add overloads
	omitting the range, and accepting a source_location.
	(rich_location::add_fixit_replace): Likewise.

From-SVN: r239861