Revert of [turbofan] Osr value typing + dynamic type checks on entry.

src/compiler/typer.cc

Index: src/compiler/typer.cc
diff --git a/src/compiler/typer.cc b/src/compiler/typer.cc
index bcacff55d9bcfd5af76fafe7e5cfe239e14dcef0..e33b7764567881f149e760262b26a9a58f2b1f87 100644
--- a/src/compiler/typer.cc
+++ b/src/compiler/typer.cc
@@ -549,19 +549,6 @@
 Type* Typer::Visitor::TypeParameter(Node* node) { return Type::Any(); }
 
 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();