Allow setting debugger breakpoints on CompareNilICs

src/x64/debug-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 215 matching lines @@
   // ----------- S t a t e -------------
   //  -- rax    : value
   //  -- rcx    : key
   //  -- rdx    : receiver
   // -----------------------------------
   Generate_DebugBreakCallHelper(
       masm, rax.bit() | rcx.bit() | rdx.bit(), 0, false);
 }
 
 
+void Debug::GenerateCompareNilICDebugBreak(MacroAssembler* masm) {
+  // Register state for CompareNil IC
+  // ----------- S t a t e -------------
+  //  -- rax    : value
+  // -----------------------------------
+  Generate_DebugBreakCallHelper(masm, rax.bit(), 0, false);
+}
+
+
 void Debug::GenerateCallICDebugBreak(MacroAssembler* masm) {
   // Register state for IC call call (from ic-x64.cc)
   // ----------- S t a t e -------------
   //  -- rcx: function name
   // -----------------------------------
   Generate_DebugBreakCallHelper(masm, rcx.bit(), 0, false);
 }
 
 
 void Debug::GenerateReturnDebugBreak(MacroAssembler* masm) {
@@ skipping 99 matching lines @@
 
 const bool Debug::kFrameDropperSupported = true;
 
 #undef __
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64