tree-object-size: Handle GIMPLE_CALL

tree-object-size: Handle GIMPLE_CALL

Handle non-constant expressions in GIMPLE_CALL arguments.  Also handle
alloca.

gcc/ChangeLog:

	PR middle-end/70090
	* tree-object-size.c (alloc_object_size): Make and return
	non-constant size expression.
	(call_object_size): Return expression or unknown based on
	whether dynamic object size is requested.

gcc/testsuite/ChangeLog:

	PR middle-end/70090
	* gcc.dg/builtin-dynamic-object-size-0.c: Add new tests.
	* gcc.dg/builtin-object-size-1.c (test1)
	[__builtin_object_size]: Alter expected result for dynamic
	object size.
	* gcc.dg/builtin-object-size-2.c (test1)
	[__builtin_object_size]: Likewise.
	* gcc.dg/builtin-object-size-3.c (test1)
	[__builtin_object_size]: Likewise.
	* gcc.dg/builtin-object-size-4.c (test1)
	[__builtin_object_size]: Likewise.

Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org>