* config/tc-mips.c (macro_build): Test for currently active
	mips16 option.
	(mips16_ip): Reject invalid opcodes.

	[ opcodes/ChangeLog ]
	* mips16-opc.c (I1, I32, I64): New shortcut defines.
	(mips16_opcodes): Change membership of instructions to their
	lowest baseline ISA.

	[ gas/testsuite/ChangeLog ]
	* gas/mips/mips.exp: Run new tests.
	* gas/mips/mips16e.s, gas/mips/mips16e.d, gas/mips/mips16e-64.s,
	gas/mips/mips16e-64.d, gas/mips/mips16e-64.l: New tests.