re PR middle-end/18191 (Struct member is not getting default-initialized)

gcc/
	PR middle-end/18191
	PR middle-end/18965
	PR middle-end/18999
	* expr.c (categorize_ctor_elements_1): Count the total number
	of elements in the constructor.
	(categorize_ctor_elements): Return it in a new argument.
	* tree.h (categorize_ctor_elements): Adjust prototype.
	* gimplify.c (gimplify_init_ctor_eval_range): New.
	(gimplify_init_ctor_eval): Gimplify RANGE_EXPR.
	(gimplify_init_constructor): Block clear the object if the
	constructor has fewer elements than the object type.  Only try
	to add assignments to individual elements when we have to.

testsuite/
	 * gcc.dg/20041219-1.c: New test.

Co-Authored-By: Andrew Pinski <pinskia@physics.uc.edu>

From-SVN: r92415