gas/testsuite/

gas/testsuite/
	* gas/i386/prefetch.s: New file.
	* gas/i386/prefetch.d: New file.
	* gas/i386/prefetch-intel.d: New file.
	* gas/i386/x86-64-prefetch.d: New file.
	* gas/i386/x86-64-prefetch-intel.d: New file.
	* gas/i386/i386.exp: Run them.

opcodes/
	* i386-dis.c (reg_table): Fill out REG_0F0D table with
	AMD-reserved cases as "prefetch".
	(MOD_0F18_REG_4, MOD_0F18_REG_5): New enum constants.
	(MOD_0F18_REG_6, MOD_0F18_REG_7): Likewise.
	(reg_table): Use those under REG_0F18.
	(mod_table): Add those cases as "nop/reserved".