Add 'domain' parameter to expand_symtabs_matching

Add 'domain' parameter to expand_symtabs_matching

Currently, expand_symtabs_matching only accepts a search_domain
parameter.  However, lookup_symbol uses a domain_enum instead, and the
two, confusingly, do quite different things -- one cannot emulate the
other.  So, this patch adds a domain_enum parameter to
expand_symtabs_matching, with UNDEF_DOMAIN used as a wildcard.

This is another step toward replacing lookup_symbol with
expand_symtabs_matching.

gdb/ChangeLog
2021-04-17  Tom Tromey  <tom@tromey.com>

	* symtab.c (global_symbol_searcher::expand_symtabs): Update.
	* symmisc.c (maintenance_expand_symtabs): Update.
	* symfile.c (expand_symtabs_matching): Update.
	* symfile-debug.c (objfile::expand_symtabs_matching): Add 'domain'
	parameter.
	* quick-symbol.h (struct quick_symbol_functions)
	<expand_symtabs_matching>: Add 'domain' parameter.
	* psymtab.c (recursively_search_psymtabs)
	(psymbol_functions::expand_symtabs_matching): Add 'domain'
	parameter.
	* psympriv.h (struct psymbol_functions) <expand_symtabs_matching>:
	Add 'domain' parameter.
	* objfiles.h (struct objfile) <expand_symtabs_matching>: Add
	'domain' parameter.
	* linespec.c (iterate_over_all_matching_symtabs): Update.
	* dwarf2/read.c (struct dwarf2_gdb_index)
	<expand_symtabs_matching>: Add 'domain' parameter.
	(struct dwarf2_debug_names_index) <expand_symtabs_matching>: Add
	'domain' parameter.
	(dw2_expand_symtabs_matching)
	(dwarf2_gdb_index::expand_symtabs_matching)
	(dw2_debug_names_iterator)
	(dwarf2_debug_names_index::expand_symtabs_matching): Add 'domain'
	parameter.