JVM IR: do not generate extension receiver parameter as ACC_MANDATED

Otherwise Java reflection is not able to load its type as a
parameterized type.

 #KT-40857 Fixed

compiler/testData/codegen/box/parametersMetadata/extensionFunction.kt

@@ -1,5 +1,6 @@
 // SKIP_JDK6
 // TARGET_BACKEND: JVM
+// IGNORE_BACKEND: JVM
 // WITH_STDLIB
 // FULL_JDK
 // PARAMETERS_METADATA
@@ -15,7 +16,7 @@ fun box(): String {
     val method = clazz.getDeclaredMethod("test", String::class.java, String::class.java)
     val parameters = method.getParameters()
 
-    if (!parameters[0].isImplicit() || parameters[0].isSynthetic()) return "wrong modifier on receiver parameter: ${parameters[0].modifiers}"
+    if (parameters[0].isImplicit() || parameters[0].isSynthetic()) return "wrong modifier on receiver parameter: ${parameters[0].modifiers}"
 
     return parameters[1].name
 }

compiler/testData/codegen/box/parametersMetadata/inlineClassMethodParameterModifiers.kt

@@ -1,5 +1,6 @@
 // SKIP_JDK6
 // TARGET_BACKEND: JVM
+// IGNORE_BACKEND: JVM
 // WITH_STDLIB
 // FULL_JDK
 // PARAMETERS_METADATA
@@ -19,10 +20,8 @@ fun box(): String {
 
     val extensionMethod = Class.forName("AKt").declaredMethods.single { it.name.contains("extension") }
     val extensionMethodParameters = extensionMethod.getParameters()
-    if (extensionMethodParameters[0].isSynthetic())
-        return "wrong modifier (synthetic) on extension receiver parameter: ${extensionMethodParameters[0].modifiers}"
-    if (!extensionMethodParameters[0].isImplicit())
-        return "wrong modifier (not implicit) on extension receiver parameter: ${extensionMethodParameters[0].modifiers}"
+    if (extensionMethodParameters[0].isSynthetic() || extensionMethodParameters[0].isImplicit())
+        return "wrong modifier on extension receiver parameter: ${extensionMethodParameters[0].modifiers}"
 
     return "OK"
 }

compiler/testData/codegen/box/parametersMetadata/kt40857_parameterizedExtensionReceiver.kt

@@ -0,0 +1,17 @@
+// SKIP_JDK6
+// TARGET_BACKEND: JVM
+// IGNORE_BACKEND: JVM
+// WITH_STDLIB
+// FULL_JDK
+// PARAMETERS_METADATA
+
+import java.lang.reflect.ParameterizedType
+
+fun List<String>.bar(i: Int) = Unit
+
+fun box(): String {
+    val function = object {}.javaClass.enclosingClass.getDeclaredMethods().single { it.name == "bar" }
+    val type = function.parameters[0].parameterizedType
+    if (type !is ParameterizedType || type.toString() != "java.util.List<java.lang.String>") return "Fail: $type ${type.javaClass}"
+    return "OK"
+}