[simplify-rtx] PR 65235: Calculate element size correctly when simplifying (vec_selec...

[simplify-rtx] PR 65235: Calculate element size correctly when simplifying (vec_select (vec_concat (const_int) (...)) [...])

	Backport from mainline
	2015-03-12  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>

	PR rtl-optimization/65235
	* simplify-rtx.c (simplify_binary_operation_1, VEC_SELECT case):
	When first element of vec_concat is const_int, calculate its size
	using second element.

	PR rtl-optimization/65235
	* gcc.target/aarch64/pr65235_1.c: New test.

From-SVN: r221511