Visium: align branch absolute instruction for the GR6

Visium: align branch absolute instruction for the GR6

This is done in order to avoid a pipeline hazard on the GR6.

gas/
	* config/tc-visium.c (md_assemble) <mode_cad>: Align instruction
	on 64-bit boundaries for the GR6.
	* testsuite/gas/visium/allinsn_gr6.s: Tweak.
	* testsuite/gas/visium/allinsn_gr6.d: Likewise.
	* testsuite/gas/visium/bra-1.d: New test.
	* testsuite/gas/visium/bra-1.s: Likewise.
	* testsuite/gas/visium/visium.exp: Run bra-1 test.