[turbofan] Fix optimized lowering of Math.imul.

src/compiler/verifier.cc

Index: src/compiler/verifier.cc
diff --git a/src/compiler/verifier.cc b/src/compiler/verifier.cc
index a788503473713c265078288116c2549db4d13c08..a8177a48573d44daec0ece02384b12632ab82c32 100644
--- a/src/compiler/verifier.cc
+++ b/src/compiler/verifier.cc
@@ -700,6 +700,12 @@ void Verifier::Visitor::Check(Node* node) {
       CheckValueInputIs(node, 1, Type::Unsigned32());
       CheckUpperIs(node, Type::Unsigned32());
       break;
+    case IrOpcode::kNumberImul:
+      // (Unsigned32, Unsigned32) -> Signed32
+      CheckValueInputIs(node, 0, Type::Unsigned32());
+      CheckValueInputIs(node, 1, Type::Unsigned32());
+      CheckUpperIs(node, Type::Signed32());
+      break;
     case IrOpcode::kNumberClz32:
       // Unsigned32 -> Unsigned32
       CheckValueInputIs(node, 0, Type::Unsigned32());