PR rtl-optimization/64286
	* ree.c (combine_reaching_defs): Move part of comment earlier,
	remove !SCALAR_INT_MODE_P check.
	(add_removable_extension): Don't add vector mode
	extensions if all uses of the source register aren't the same
	vector extensions.

	* gcc.target/i386/avx2-pr64286.c: New test.

From-SVN: r219550