X87: Debugger: use debug break slots to break at function exit.

src/x87/assembler-x87.h

Index: src/x87/assembler-x87.h
diff --git a/src/x87/assembler-x87.h b/src/x87/assembler-x87.h
index 932dac702ab4b7715704cc1a075292bf39b6d9d4..6d631785d689f28cfc34de27b5afc40a78e96ecb 100644
--- a/src/x87/assembler-x87.h
+++ b/src/x87/assembler-x87.h
@@ -524,9 +524,6 @@ class Assembler : public AssemblerBase {
   // of that call in the instruction stream.
   inline static Address target_address_from_return_address(Address pc);
 
-  // Return the code target address of the patch debug break slot
-  inline static Address break_address_from_return_address(Address pc);
-
   // This sets the branch destination (which is in the instruction on x86).
   // This is for calls and branches within generated code.
   inline static void deserialization_set_special_target_at(
@@ -544,21 +541,16 @@ class Assembler : public AssemblerBase {
   // Distance between the address of the code target in the call instruction
   // and the return address
   static const int kCallTargetAddressOffset = kPointerSize;
-  // Distance between start of patched return sequence and the emitted address
-  // to jump to.
-  static const int kPatchReturnSequenceAddressOffset = 1;  // JMP imm32.
-
-  // Distance between start of patched debug break slot and the emitted address
-  // to jump to.
-  static const int kPatchDebugBreakSlotAddressOffset = 1;  // JMP imm32.
 
   static const int kCallInstructionLength = 5;
-  static const int kPatchDebugBreakSlotReturnOffset = kPointerSize;
-  static const int kJSReturnSequenceLength = 6;
 
   // The debug break slot must be able to contain a call instruction.
   static const int kDebugBreakSlotLength = kCallInstructionLength;
 
+  // Distance between start of patched debug break slot and the emitted address
+  // to jump to.
+  static const int kPatchDebugBreakSlotAddressOffset = 1;  // JMP imm32.
+
   // One byte opcode for test al, 0xXX.
   static const byte kTestAlByte = 0xA8;
   // One byte opcode for nop.
@@ -951,16 +943,11 @@ class Assembler : public AssemblerBase {
     return pc_offset() - label->pos();
   }
 
-  // Mark address of the ExitJSFrame code.
-  void RecordJSReturn();
-
   // Mark generator continuation.
   void RecordGeneratorContinuation();
 
   // Mark address of a debug break slot.
-  void RecordDebugBreakSlot();
-  void RecordDebugBreakSlotForCall(int argc);
-  void RecordDebugBreakSlotForConstructCall();
+  void RecordDebugBreakSlot(RelocInfo::Mode mode, int argc = 0);
 
   // Record a comment relocation entry that can be used by a disassembler.
   // Use --code-comments to enable.