C99 testsuite readiness: Some verified test case adjustments

C99 testsuite readiness: Some verified test case adjustments

The updated test cases still reproduce the bugs with old compilers.

gcc/testsuite/

	* gcc.c-torture/compile/pc44485.c (func_21): Add missing cast.
	* gcc.c-torture/compile/pr106101.c: Use builtins to avoid
	calls to undeclared functions.  Change type of yyvsp to
	char ** and introduce yyvsp1 to avoid type errors.
	* gcc.c-torture/execute/pr111331-1.c: Add missing int.
	* gcc.dg/pr100512.c: Unreduce test case and suppress only
	-Wpointer-to-int-cast.
	* gcc.dg/pr103003.c: Likewise.
	* gcc.dg/pr103451.c: Add cast to long and suppress
	-Wdiv-by-zero only.
	* gcc.dg/pr68435.c: Avoid implicit int and missing
	static function implementation warning.