[JVM] Fix caching of defined classes by the ByteClassLoader

- Actually use any cached class, read or defined...
- We need to use getName when name is null in either case, not
  getCanonicalName, so we avoid name clashing with static classes.

src/vm/jvm/runtime/org/raku/nqp/runtime/ByteClassLoader.java

@@ -33,23 +33,24 @@ public Class<?> getMade(String name) {
     }
 
     public Class<?> setMade(String name, Class<?> klass) {
-        if (name != null)
-            made.put(name, new SoftReference(klass));
+        if (name == null)
+            name = klass.getName();
+        made.put(name, new SoftReference(klass));
         return klass;
     }
 
     public Class<?> getRead(ClassLoader child, String name) {
         if (name != null && made.containsKey(name))
             return made.get(name).get();
         if (child != null && read.containsKey(child))
-            if (made.containsKey(name = read.get(name)))
+            if (made.containsKey(name = read.get(child)))
                 return made.get(name).get();
         return null;
     }
 
     public Class<?> setRead(ClassLoader child, String name, Class<?> klass) {
         if (name == null)
-            name = klass.getCanonicalName();
+            name = klass.getName();
         if (child != null)
             read.put(child, name);
         made.put(name, new SoftReference(klass));
@@ -58,6 +59,6 @@ public Class<?> setRead(ClassLoader child, String name, Class<?> klass) {
 
     public Class<?> defineClass(String name, byte[] bytes) throws ClassFormatError {
         Class<?> made = getMade(name);
-        return made == null ? setMade(name, defineClass(name, bytes, 0, bytes.length)) : null;
+        return made == null ? setMade(name, defineClass(name, bytes, 0, bytes.length)) : made;
     }
 }