MIPS16/opcodes: Reformat raw EXTEND and undecoded output

MIPS16/opcodes: Reformat raw EXTEND and undecoded output

Use a tab rather than a space to separate `extend' and its uninterpreted
argument output, like with regular instructions.  Separate hexadecimal
halves of undecoded extended instructions output with a space instead of
presenting them concatenated.

	opcodes/
	* mips-dis.c (print_insn_mips16): Use a tab rather than a space
	to separate `extend' and its uninterpreted argument output.
	Separate hexadecimal halves of undecoded extended instructions
	output.

	binutils/
	* testsuite/binutils-all/mips/mips16-extend-noinsn.d: New test.
	* testsuite/binutils-all/mips/mips16-extend-noinsn.s: New test
	source.
	* testsuite/binutils-all/mips/mips.exp: Run the new test.