re PR ipa/82801 (Internal compiler error with Eigen and __attribute__((always_inline...

re PR ipa/82801 (Internal compiler error with Eigen and __attribute__((always_inline, flatten)))

	PR ipa/82801
	PR ipa/83346
	* ipa-inline.c (flatten_remove_node_hook): New function.
	(ipa_inline): Keep only nodes with flatten attribute at the end of
	the array in the order from ipa_reverse_postorder, only walk that
	portion of array for flattening, if there is more than one such
	node, temporarily register a removal hook and ignore removed nodes.

	* g++.dg/ipa/pr82801.C: New test.

From-SVN: r255805