MIPS16/opcodes: Correct 64-bit macros' ISA membership

MIPS16/opcodes: Correct 64-bit macros' ISA membership

Limit the DDIV, DDIVU, DREM, DREMU and DSUBU macros to the MIPS III
rather than MIPS I ISA.  These macros expand to machine code sequences
including 64-bit instructions which require a 64-bit ISA.  Entries for
those instructions are already correctly marked, however the marking is
ignored if entries are used in the process of macro expansion rather
than directly, making it possible to indirectly produce 64-bit machine
code even when output requested has been limited to a 32-bit ISA.

	opcodes/
	* mips16-opc.c (mips16_opcodes): Set membership to I3 rather
	than I1 for the "ddiv", "ddivu", "drem", "dremu" and "dsubu"
	INSN_MACRO entries.

	gas/
	* testsuite/gas/mips/mips16-macro.l: New list test.
	* testsuite/gas/mips/mips.exp: Run the new test.