Fix #15199: Exclude JavaDefined Modules from bridge generation.

JavaDefined modules are imaginary symbols that dotc uses to refer
to static methods of Java classes. They have no reification, and
therefore it makes no sense for them to participate in bridge
generation.

Author: sjrd

compiler/src/dotty/tools/dotc/transform/Bridges.scala

@@ -37,7 +37,7 @@ class Bridges(root: ClassSymbol, thisPhase: DenotTransformer)(using Context) {
     override def parents = Array(root.superClass)
 
     override def exclude(sym: Symbol) =
-      !sym.isOneOf(MethodOrModule) || super.exclude(sym)
+      !sym.isOneOf(MethodOrModule) || sym.isAllOf(Module | JavaDefined) || super.exclude(sym)
 
     override def canBeHandledByParent(sym1: Symbol, sym2: Symbol, parent: Symbol): Boolean =
       OverridingPairs.isOverridingPair(sym1, sym2, parent.thisType)

tests/run/i15199/Child_1.java

@@ -0,0 +1,4 @@
+public class Child_1 extends Parent_1 {
+  public class Inner {
+  }
+}

tests/run/i15199/Parent_1.java

@@ -0,0 +1,4 @@
+public class Parent_1 {
+  public class Inner {
+  }
+}

tests/run/i15199/Test_2.scala

@@ -0,0 +1,5 @@
+class ScalaChild extends Child_1
+
+@main def Test(): Unit =
+  val methods = classOf[ScalaChild].getDeclaredMethods()
+  assert(methods.length == 0, methods.mkString(", "))