[turbofan] Replace uninitialized JSConstruct nodes with SOFT deopt.

test/mjsunit/ignition/throw-if-not-hole.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: --opt --allow-natives-syntax --no-always-opt
 
 class A {
   constructor() { }
 }
 class B extends A {
   constructor(call_super) {
     super();
     if (call_super) {
       super();
     }
   }
 }
 
 test = new B(0);
 test = new B(0);
+assertThrowsEquals(() => {new B(1)}, ReferenceError());
+assertThrowsEquals(() => {new B(1)}, ReferenceError());
 %OptimizeFunctionOnNextCall(B);
 test = new B(0);
 assertOptimized(B);
 // Check that hole checks are handled correctly in optimized code.
 assertThrowsEquals(() => {new B(1)}, ReferenceError());
 assertOptimized(B);