analyzer: Fix regression bug after r14-1632-g9589a46ddadc8b [PR110198]

analyzer: Fix regression bug after r14-1632-g9589a46ddadc8b [PR110198]

g++.dg/analyzer/PR100244.C was failing after a patch of PR109439.
The reason was a spurious preemptive return of get_store_value upon
out-of-bounds read that was preventing further checks. Now instead,
a boolean value check_poisoned goes to false when a OOB is detected,
and is later on given to get_or_create_initial_value.

gcc/analyzer/ChangeLog:
	PR analyzer/110198
	* region-model-manager.cc
	(region_model_manager::get_or_create_initial_value): Take an
	optional boolean value to bypass poisoning checks
	* region-model-manager.h: Update declaration of the above function.
	* region-model.cc (region_model::get_store_value): No longer returns
	on OOB, but rather gives a boolean to get_or_create_initial_value.
	(region_model::check_region_access): Update docstring.
	(region_model::check_region_for_write): Update docstring.

Signed-off-by: benjamin priour <priour.be@gmail.com>