[csa] Add Unreachable() and use it after throw sites

src/compiler/machine-graph-verifier.cc

Index: src/compiler/machine-graph-verifier.cc
diff --git a/src/compiler/machine-graph-verifier.cc b/src/compiler/machine-graph-verifier.cc
index eb07f53f2d5b5c906c227116eec3a1bb523ca293..2d5fce5f0ad939f92bfa50032f4eed91b316b676 100644
--- a/src/compiler/machine-graph-verifier.cc
+++ b/src/compiler/machine-graph-verifier.cc
@@ -520,6 +520,9 @@ class MachineRepresentationChecker {
             }
             break;
           }
+          case IrOpcode::kThrow:
+            CheckValueInputIsTagged(node, 0);
+            break;
           case IrOpcode::kTypedStateValues:
           case IrOpcode::kFrameState:
             break;