Refactor BreakLocationIterator.

src/mips/assembler-mips.h

Index: src/mips/assembler-mips.h
diff --git a/src/mips/assembler-mips.h b/src/mips/assembler-mips.h
index 296311273081329ac8401ce96b91b80f68e5bcae..8f2e9983d533f5b17729cc8249b64e54c1d6a8e3 100644
--- a/src/mips/assembler-mips.h
+++ b/src/mips/assembler-mips.h
@@ -591,6 +591,8 @@ class Assembler : public AssemblerBase {
   // Number of instructions used for the JS return sequence. The constant is
   // used by the debugger to patch the JS return sequence.
   static const int kJSReturnSequenceInstructions = 7;
+  static const int kJSReturnSequenceLength =
+      kJSReturnSequenceInstructions * kInstrSize;
   static const int kDebugBreakSlotInstructions = 4;
   static const int kDebugBreakSlotLength =
       kDebugBreakSlotInstructions * kInstrSize;