Abstract out fetching of break_address in debug mode

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 2ba3ef7166f2f9023adb77c5d128dd12a51768bc..d058fde8ed887a1ec019dc72a449e050278b5077 100644
--- a/src/mips/assembler-mips.h
+++ b/src/mips/assembler-mips.h
@@ -561,6 +561,9 @@ class Assembler : public AssemblerBase {
   // to jump to.
   static const int kPatchDebugBreakSlotAddressOffset =  0 * kInstrSize;
 
+  // Return the code target address of the patch debug break slot
+  inline static Address break_address_from_break_address(Address pc);
+
   // Difference between address of current opcode and value read from pc
   // register.
   static const int kPcLoadDelta = 4;