2019-06-06  Andrew Stubbs  <ams@codesourcery.com>

	gcc/
	* config.gcc (amdgcn-*-*): Allow --with-arch=gfx906.
	* config/gcn/gcn.opt (gpu_type): Add gfx906.
	* config/gcn/t-gcn-hsa (MULTILIB_OPTIONS): Add gfx906 multilib.
	(MULTILIB_DIRNAMES): Rename gcn5 to gfx900.
	Add gfx906.

From-SVN: r272007