MIPS: Fix 'Optimize simulator.'

MIPS: Fix 'Optimize simulator.'

For simulator optimization we modified Instruction::InstructionType() function so a simpler but less complete InstructionType() function used by default. This fix enables the full InstructionType checking to properly decode a dd-constant label as unsupported opcode, rather than aborting.

BUG=chromium:528875
LOG=NO

Review URL: https://codereview.chromium.org/1314673010

Cr-Commit-Position: refs/heads/master@{#30644}