Fix byte array memory leak from MemoryBasedClassLoader

40 Mb of bytes of preloaded compiler classes during the compilation become 16
Mb after this change

This is a slightly reworked version of 58b033d (reverted in 3f05419). The
problem in that commit was that URLClassLoader did not work in the fashion
MemoryBasedClassLoader was designed to work (child first, parent last). So some
resource was found in an incorrect jar which was causing the compiler to break

compiler/util/src/org/jetbrains/kotlin/utils/PathUtil.java

@@ -135,7 +135,11 @@ public class PathUtil {
 
     @NotNull
     public static File getResourcePathForClass(@NotNull Class aClass) {
-        String resourceRoot = PathManager.getResourceRoot(aClass, "/" + aClass.getName().replace('.', '/') + ".class");
+        String path = "/" + aClass.getName().replace('.', '/') + ".class";
+        String resourceRoot = PathManager.getResourceRoot(aClass, path);
+        if (resourceRoot == null) {
+            throw new IllegalStateException("Resource not found: " + path);
+        }
         return new File(resourceRoot).getAbsoluteFile();
     }