c++: -frange-for-ext-temps and reused temps [PR118856]

c++: -frange-for-ext-temps and reused temps [PR118856]

Some things in the front-end use a TARGET_EXPR to create a temporary, then
refer to its TARGET_EXPR_SLOT separately later; in this testcase,
maybe_init_list_as_range does.  So we need to handle that pattern in
extend_all_temps.

	PR c++/118856

gcc/cp/ChangeLog:

	* call.cc (struct extend_temps_data): Add var_map.
	(extend_all_temps): Adjust.
	(set_up_extended_ref_temp): Make walk_data void*.
	(extend_temps_r): Remap variables.  Handle pset here.
	Extend all TARGET_EXPRs.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp23/range-for9.C: New test.