MIPS: Added the stop() instruction with same behavior as on Arm simulator.

src/mips/macro-assembler-mips.cc

Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index 8b342a28453617abb8db72bb539e2b530a1ce04f..e2931008bfbaf8c28c1a9699c70d7c01cb045975 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -670,14 +670,6 @@ void MacroAssembler::li(Register rd, Operand j, bool gen2instr) {
 }
 
 
-// Exception-generating instructions and debugging support.
-void MacroAssembler::stop(const char* msg) {
-  // TO_UPGRADE: Just a break for now. Maybe we could upgrade it.
-  // We use the 0x54321 value to be able to find it easily when reading memory.
-  break_(0x54321);
-}
-
-
 void MacroAssembler::MultiPush(RegList regs) {
   int16_t NumSaved = 0;
   int16_t NumToPush = NumberOfBitsSet(regs);