analyzer: fix missing leak after call to strsep [PR100615]

analyzer: fix missing leak after call to strsep [PR100615]

PR analyzer/100615 reports a missing leak diagnostic.
The issue is that the code calls strsep which the analyzer doesn't
have special knowledge of, and so conservatively assumes that it
could free the pointer, so drops malloc state for it.

Properly "teaching" the analyzer about strsep would require it
to support bifurcating state at a call, which is currently fiddly to
do, so for now this patch notes that strsep doesn't affect the
malloc state machine, allowing the analyzer to correctly detect the leak.

gcc/analyzer/ChangeLog:
	PR analyzer/100615
	* sm-malloc.cc: Include "analyzer/function-set.h".
	(malloc_state_machine::on_stmt): Call unaffected_by_call_p and
	bail on the functions it recognizes.
	(malloc_state_machine::unaffected_by_call_p): New.

gcc/testsuite/ChangeLog:
	PR analyzer/100615
	* gcc.dg/analyzer/pr100615.c: New test.