[gdb/symtab] Use lambda function instead of addrmap_foreach_check

[gdb/symtab] Use lambda function instead of addrmap_foreach_check

Use a lambda function instead of addrmap_foreach_check,
which removes the need for static variables.

Also remove unnecessary static on local var temp_obstack in test_addrmap.

gdb/ChangeLog:

2021-08-04  Tom de Vries  <tdevries@suse.de>

	* addrmap.c (addrmap_foreach_check): Remove.
	(array, val1, val2): Move ...
	(test_addrmap): ... here.  Remove static on temp_obstack.  Use lambda
	function instead of addrmap_foreach_check.