Painless: Fix method references to ctor with the new LambdaBootstrap …

…and cleanup code (#24406)

* Fix wrong delegation to constructors when compiling lambdas with method references to ctors. Also remove the get$lambda factory.
* Cleanup code and remove unneeded transformations between binary and internal class names (uses ASM Type class instead)
* Cleanup Exception handling
* Simplification by moving the type adaption to the outside
* Remove STATIC access flag from our Lambda class (not required and also officially not allowed)
* Move the lambda counter to the classloader, so we have a per-script lambda ID
* Change Codesource of generated lambdas to be consistent

modules/lang-painless/src/main/java/org/elasticsearch/painless/Compiler.java

@@ -30,6 +30,7 @@
 import java.security.SecureClassLoader;
 import java.security.cert.Certificate;
 import java.util.BitSet;
+import java.util.concurrent.atomic.AtomicInteger;
 
 import static org.elasticsearch.painless.WriterConstants.CLASS_NAME;
 
@@ -66,6 +67,8 @@ final class Compiler {
      * A secure class loader used to define Painless scripts.
      */
     static final class Loader extends SecureClassLoader {
+        private final AtomicInteger lambdaCounter = new AtomicInteger(0);
+
         /**
          * @param parent The parent ClassLoader.
          */
@@ -90,7 +93,15 @@ Class<? extends PainlessScript> defineScript(String name, byte[] bytes) {
          * @return A Class object.
          */
         Class<?> defineLambda(String name, byte[] bytes) {
-            return defineClass(name, bytes, 0, bytes.length);
+            return defineClass(name, bytes, 0, bytes.length, CODESOURCE);
+        }
+
+        /**
+         * A counter used to generate a unique name for each lambda
+         * function/reference class in this classloader.
+         */
+        int newLambdaIdentifier() {
+            return lambdaCounter.getAndIncrement();
         }
     }