fix special case for null pointer constants in cond expressions

	Section 6.5.15 of the C99 spec requires that if
	one argument of a ?: expression is a null pointer
	constant, and the other has a pointer type T*, then
	the type of the expression is T*.

	We were attempting to follow this rule, however,
	we only handled literal expressions when checking
	for null pointers.

	This change looks through casts, so 'nil' and 'NULL',
	and their expansion '(void*)0' are all detected as
	null pointer constants.

0 files changed, 0 insertions, 0 deletions