[compiler] Fix editing mistake.

In my previous typer changes I had forgotten to remove one line.

R=jarin@chromium.org

Bug: 
Change-Id: If9e9984c23273707548c2d7329f9fa715a170a90
Reviewed-on: https://chromium-review.googlesource.com/800270Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49761}

src/compiler/typer.cc

@@ -1082,7 +1082,6 @@ Type* Typer::Visitor::JSBitwiseXorTyper(Type* lhs, Type* rhs, Typer* t) {
 
 
 Type* Typer::Visitor::JSShiftLeftTyper(Type* lhs, Type* rhs, Typer* t) {
-  return NumberShiftLeft(ToNumber(lhs, t), ToNumber(rhs, t), t);
   lhs = ToNumeric(lhs, t);
   rhs = ToNumeric(rhs, t);
   if (lhs->Is(Type::Number()) && rhs->Is(Type::Number())) {