[turbofan] Remove deprecated --turbo-from-bytecode flag.

test/mjsunit/regress/regress-5252.js

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --allow-natives-syntax --ignition --ignition-osr --turbo-from-bytecode
+// Flags: --allow-natives-syntax --ignition --ignition-osr
 
 (function TestNonLoopyLoop() {
   function f() {
     do {
       %OptimizeOsr();
       return 23;
     } while(false)
   }
   assertEquals(23, f());
   assertEquals(23, f());
 })();
 
 (function TestNonLoopyGenerator() {
   function* g() {
     do {
       %OptimizeOsr();
       yield 23;
       yield 42;
     } while(false)
     return 999;
   }
   var gen = g();
   assertEquals({ value:23, done:false }, gen.next());
   assertEquals({ value:42, done:false }, gen.next());
   assertEquals({ value:999, done:true }, gen.next());
 })();