* Converted conditional-trap MIPS opcodes to extra-operand variety also.

* Converted conditional-trap MIPS opcodes to extra-operand variety also.
* Bonus test cases to confirm behavior.

[ChangeLog]
Thu May  7 12:50:33 1998  Frank Ch. Eigler  <fche@cygnus.com>

	* config/tc-mips.c (validate_mips_insn): Removed hack
	for previously inaccessible bitfields in some INSN_TRAP
	instructions.

[testsuite/ChangeLog]

Thu May  7 13:05:25 1998  Frank Ch. Eigler  <fche@cygnus.com>

	* gas/mips/break20.[sd]: New tests for 20-bit operand break and
 	sddbp instructions.
	* gas/mips/trap20.[sd]: New tests for 20-bit operand trap
 	instructions.
	* gas/mips/mips.exp: Run them.