[turbofan] Introduces the SpeculativeNumberShiftLeft opcode.

src/compiler/typer.cc

Index: src/compiler/typer.cc
diff --git a/src/compiler/typer.cc b/src/compiler/typer.cc
index 9ae1005f532634c63ac26b613968821d284124af..3679403f41f3a762b26a1cb4667ee20c2e988de2 100644
--- a/src/compiler/typer.cc
+++ b/src/compiler/typer.cc
@@ -1556,6 +1556,10 @@ Type* Typer::Visitor::TypeSpeculativeNumberModulus(Node* node) {
   return Type::Number();
 }
 
+Type* Typer::Visitor::TypeSpeculativeNumberShiftLeft(Node* node) {
+  return Type::Signed32();
+}
+
 Type* Typer::Visitor::TypeNumberMultiply(Node* node) { return Type::Number(); }
 
 Type* Typer::Visitor::TypeNumberDivide(Node* node) { return Type::Number(); }