analyzer: Standalone OOB-warning [PR109437, PR109439]

analyzer: Standalone OOB-warning [PR109437, PR109439]

This patch enhances -Wanalyzer-out-of-bounds that is no longer paired
with a -Wanalyzer-use-of-uninitialized-value on out-of-bounds-read.

This also fixes PR analyzer/109437.
Before there could always be at most one OOB-read warning per frame because
-Wanalyzer-use-of-uninitialized-value always terminates the analysis
path.

PR 109439

gcc/analyzer/ChangeLog:

	* bounds-checking.cc (region_model::check_symbolic_bounds): Returns whether the BASE_REG
	region access was OOB.
	(region_model::check_region_bounds): Likewise.
	* region-model.cc (region_model::get_store_value): Creates an
	unknown svalue on OOB-read access to REG.
	(region_model::check_region_access): Returns whether an unknown svalue needs be created.
	(region_model::check_region_for_read): Passes check_region_access return value.
	* region-model.h: Update prior function definitions.

gcc/testsuite/ChangeLog:

	* gcc.dg/analyzer/out-of-bounds-2.c: Cleaned test for uninitialized-value warning
	* gcc.dg/analyzer/out-of-bounds-5.c: Likewise.
	* gcc.dg/analyzer/pr101962.c: Likewise.
	* gcc.dg/analyzer/realloc-5.c: Likewise.
	* gcc.dg/analyzer/pr109439.c: New test.