Refactor BreakLocationIterator.

src/mips64/assembler-mips64.h

Index: src/mips64/assembler-mips64.h
diff --git a/src/mips64/assembler-mips64.h b/src/mips64/assembler-mips64.h
index 09f29c2e8131c829bef243301796ef7874eed226..fbcf59a98245ea61d67205abb445093fd92746c9 100644
--- a/src/mips64/assembler-mips64.h
+++ b/src/mips64/assembler-mips64.h
@@ -585,6 +585,8 @@ 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 = 6;
   static const int kDebugBreakSlotLength =
       kDebugBreakSlotInstructions * kInstrSize;