The outgoing stack slot size may be different from the BLKmode argument
size due to parameter alignment.  Check partial != 0 for BLKmode argument
passed on stack.

gcc/

	PR middle-end/117098
	* calls.cc (store_one_arg): Check partial != 0 for BLKmode argument
	passed on stack.

gcc/testsuite/

	PR middle-end/117098
	* gcc.dg/sibcall-12.c: New test.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>