Fixes for test(@JvmStatic -> const), fix for prototype assign

j2k/src/org/jetbrains/kotlin/j2k/Converter.kt

@@ -311,7 +311,7 @@ class Converter private constructor(
         //TODO: annotations from getter/setter?
         val annotations = field?.let { convertAnnotations(it) } ?: Annotations.Empty
 
-        val modifiers = propertyInfo.modifiers + (field?.let{ specialModifiersCase(field) } ?: Modifiers.Empty)
+        val modifiers = (propertyInfo.modifiers + (field?.let{ specialModifiersCase(field) } ?: Modifiers.Empty))
 
         val name = propertyInfo.identifier
         if (field is PsiEnumConstant) {

j2k/src/org/jetbrains/kotlin/j2k/ast/Modifier.kt

@@ -68,7 +68,7 @@ class Modifiers(modifiers: Collection<Modifier>) : Element() {
     fun accessModifier(): Modifier? = modifiers.firstOrNull { it in ACCESS_MODIFIERS }
 
     operator fun plus(other: Modifiers): Modifiers {
-        return Modifiers(this.modifiers + other.modifiers).assignNoPrototype()
+        return Modifiers(this.modifiers + other.modifiers).assignPrototypesFrom(this)
     }
 
     companion object {

j2k/testData/fileOrElement/issues/kt-837.kt

@@ -11,6 +11,6 @@ class Language(protected var code: String) : Serializable {
     companion object {
         var ENGLISH = Language("en")
         var SWEDISH = Language("sv")
-        @JvmStatic private val serialVersionUID = -2442762969929206780L
+        private const val serialVersionUID = -2442762969929206780L
     }
 }