X87: [turbofan] Add DebugBreak machine operator and support.

  port 78b1585f (r36355)

  original commit message:

BUG=

Review-Url: https://codereview.chromium.org/1998013002
Cr-Commit-Position: refs/heads/master@{#36388}

src/compiler/x87/code-generator-x87.cc

@@ -606,6 +606,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchTableSwitch:
       AssembleArchTableSwitch(instr);
       break;
+    case kArchDebugBreak:
+      __ int3();
+      break;
     case kArchNop:
     case kArchThrowTerminator:
       // don't emit code for nops.