Abstract out fetching of break_address in debug mode

src/mips/assembler-mips-inl.h

Index: src/mips/assembler-mips-inl.h
diff --git a/src/mips/assembler-mips-inl.h b/src/mips/assembler-mips-inl.h
index cf8865b875d690db6e35dcad7fc6e74b06d425f6..b368dd86091794c688672b17c8fcb868a4957048 100644
--- a/src/mips/assembler-mips-inl.h
+++ b/src/mips/assembler-mips-inl.h
@@ -190,6 +190,11 @@ Address Assembler::target_address_from_return_address(Address pc) {
 }
 
 
+Address Assembler::break_address_from_return_address(Address pc) {
+  return pc - Assembler::kPatchDebugBreakSlotReturnOffset;
+}
+
+
 Object* RelocInfo::target_object() {
   ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
   return reinterpret_cast<Object*>(Assembler::target_address_at(pc_, host_));