* gcc.dg/tree-ssa/loop-36.c: Reduce amount of iterations to 2 so unrolling
	still happens.
	* gcc.dg/ipa/ipacost-1.c: Prevent inlining
	* gcc.dg/ipa/ipacost-2.c: Likewise.
	* gcc.dg/vect/slp-3.c: Loop is no longer unrolled.

	* tree-inline.c (estimate_operator_cost): Add operands;
	when division happens by constant, it is cheap.
	(estimate_num_insns): Loads and stores are not having cost of 0;
	EH magic stuff is cheap; when computing runtime cost of switch,
	use log2 base of amount of its cases; builtin_expect has cost of 0;
	compute cost for moving return value of call.
	(init_inline_once): Initialize time_based flags.
	* tree-inline.h (eni_weights_d): Add time_based flag.

From-SVN: r147436