Fixes issue with variadic functions on win64 if the argument before the variadic function is > 8 byte (issue 9495)
Merge remote-tracking branch 'remotes/upstream/master' into pull9495

Conflicts:
	src/func.c
-Added test case for bug 9495
-Using Target::ptrsize instead of hardcoded constant
test9495 should not be compiled with -release
Merge pull request #1657 from Ingrater/pull9495

9495: Fixes issue with variadic functions on win64