[turbofan] Introduce a SpeculativeToNumber operator.

src/compiler/js-typed-lowering.h

Index: src/compiler/js-typed-lowering.h
diff --git a/src/compiler/js-typed-lowering.h b/src/compiler/js-typed-lowering.h
index cb687c0427394b8e4d1712bbcf8d9a44951e6865..98d71c3ed99d5ac1f30698442894078ed21b4497 100644
--- a/src/compiler/js-typed-lowering.h
+++ b/src/compiler/js-typed-lowering.h
@@ -84,6 +84,7 @@ class V8_EXPORT_PRIVATE JSTypedLowering final
   Reduction ReduceUI32Shift(Node* node, Signedness signedness);
   Reduction ReduceCreateConsString(Node* node);
   Reduction ReduceSpeculativeNumberAdd(Node* node);
+  Reduction ReduceSpeculativeNumberMultiply(Node* node);
   Reduction ReduceSpeculativeNumberBinop(Node* node);
   Reduction ReduceSpeculativeNumberComparison(Node* node);