Undo delay slot filling and use compact branches in selected cases.

Undo delay slot filling and use compact branches in selected cases.

gcc/
	* config/mips/mips.c (mips_breakable_sequence_p): New function.
	(mips_break_sequence): New function.
	(mips_reorg_process_insns) Use them. Use compact branches in selected
          situations.

gcc/testsuite/
        * gcc.target/mips/split-ds-sequence.c: New test.

From-SVN: r230160