8365594: Strengthen Universe klasses asserts to catch bootstrapping errors earlier

Reviewed-by: coleenp, ayang

Author: shipilev

src/hotspot/share/memory/oopFactory.cpp

@@ -73,7 +73,6 @@ typeArrayOop oopFactory::new_longArray(int length, TRAPS) {
 
 // create java.lang.Object[]
 objArrayOop oopFactory::new_objectArray(int length, TRAPS)  {
-  assert(Universe::objectArrayKlass() != nullptr, "Too early?");
   return Universe::objectArrayKlass()->allocate_instance(length, THREAD);
 }
 

src/hotspot/share/memory/universe.hpp

@@ -185,15 +185,24 @@ class Universe: AllStatic {
   static TypeArrayKlass* floatArrayKlass()       { return typeArrayKlass(T_FLOAT); }
   static TypeArrayKlass* doubleArrayKlass()      { return typeArrayKlass(T_DOUBLE); }
 
-  static ObjArrayKlass* objectArrayKlass()       { return _objectArrayKlass; }
+  static ObjArrayKlass* objectArrayKlass() {
+    ObjArrayKlass* k = _objectArrayKlass;
+    assert(k != nullptr, "Object array klass should be initialized; too early?");
+    return k;
+  }
 
-  static Klass* fillerArrayKlass()               { return _fillerArrayKlass; }
+  static Klass* fillerArrayKlass() {
+    Klass* k = _fillerArrayKlass;
+    assert(k != nullptr, "Filler array class should be initialized; too early?");
+    return k;
+  }
 
   static TypeArrayKlass* typeArrayKlass(BasicType t) {
     assert((uint)t >= T_BOOLEAN, "range check for type: %s", type2name(t));
     assert((uint)t < T_LONG+1,   "range check for type: %s", type2name(t));
-    assert(_typeArrayKlasses[t] != nullptr, "domain check");
-    return _typeArrayKlasses[t];
+    TypeArrayKlass* k = _typeArrayKlasses[t];
+    assert(k != nullptr, "Type array class should be initialized; too early?");
+    return k;
   }
 
   // Known objects in the VM