analyzer: fix -Wanalyzer-va-list-exhausted false +ve on va_arg in subroutine [PR106383]
gcc/analyzer/ChangeLog:
PR analyzer/106383
* varargs.cc (region_model::impl_call_va_arg): When determining if
we're doing interprocedural analysis, use the stack depth of the
frame in which va_start was called, rather than the current stack
depth.
gcc/testsuite/ChangeLog:
PR analyzer/106383
* gcc.dg/analyzer/stdarg-3.c: New test.
Signed-off-by: David Malcolm <dmalcolm@redhat.com>