[turbofan] Rip out the unused OsrGuard node.

src/compiler/typer.cc

Index: src/compiler/typer.cc
diff --git a/src/compiler/typer.cc b/src/compiler/typer.cc
index 85e5a170600791973321324decabda1729aceaab..d514ef02dbe381bff503d8e782efa27a9cf385bd 100644
--- a/src/compiler/typer.cc
+++ b/src/compiler/typer.cc
@@ -607,19 +607,6 @@ Type* Typer::Visitor::TypeParameter(Node* node) {
 
 Type* Typer::Visitor::TypeOsrValue(Node* node) { return Type::Any(); }
 
-Type* Typer::Visitor::TypeOsrGuard(Node* node) {
-  switch (OsrGuardTypeOf(node->op())) {
-    case OsrGuardType::kUninitialized:
-      return Type::None();
-    case OsrGuardType::kSignedSmall:
-      return Type::SignedSmall();
-    case OsrGuardType::kAny:
-      return Type::Any();
-  }
-  UNREACHABLE();
-  return nullptr;
-}
-
 Type* Typer::Visitor::TypeRetain(Node* node) {
   UNREACHABLE();
   return nullptr;