PPC/S390: [turbofan] Add DebugBreak machine operator and support

port 78b1585f

R=danno@chromium.org, joransiu@ca.ibm.com, michael_dawson@ca.ibm.com, mbrandy@us.ibm.com
BUG=

Review-Url: https://codereview.chromium.org/1993273002
Cr-Commit-Position: refs/heads/master@{#36376}

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

@@ -874,6 +874,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       AssembleArchTableSwitch(instr);
       DCHECK_EQ(LeaveRC, i.OutputRCBit());
       break;
+    case kArchDebugBreak:
+      __ stop("kArchDebugBreak");
+      break;
     case kArchNop:
     case kArchThrowTerminator:
       // don't emit code for nops.

src/compiler/s390/code-generator-s390.cc

@@ -720,6 +720,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchTableSwitch:
       AssembleArchTableSwitch(instr);
       break;
+    case kArchDebugBreak:
+      __ stop("kArchDebugBreak");
+      break;
     case kArchNop:
     case kArchThrowTerminator:
       // don't emit code for nops.