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
 }