Regular modifier checker implemented (initial version). A set of tests fixed accordingly.

Most of modifier diagnostic is expressed by REDUNDANT_MODIFIER, INCOMPATIBLE_MODIFIERS, REPEATED_MODIFIER, WRONG_MODIFIER_TARGET, WRONG_MODIFIER_PARENT.
A set of modifier diagnostics is not in use now (but not deleted yet).

compiler/testData/codegen/box/classes/delegation4.kt

@@ -1,8 +1,8 @@
-open interface First {
+interface First {
   public open fun foo() : Int
 }
 
-open interface Second : First {
+interface Second : First {
   public open fun bar() : Int
 }
 

compiler/testData/codegen/box/superConstructorCall/deepLocalHierarchy.kt

@@ -1,5 +1,5 @@
 fun box(): String {
-    open interface L1 {
+    interface L1 {
         fun foo(): String
     }
 

compiler/testData/codegen/boxInline/complex/use.2.kt

@@ -9,7 +9,7 @@ public  class Output(val d: Data) : Closeable {
     public fun doOutput(data: Int): Int = data
 }
 
-public open interface Closeable {
+public interface Closeable {
     open public fun close() {}
 }
 

compiler/testData/codegen/boxInline/complex/with.2.kt

@@ -11,7 +11,7 @@ public  class Output(val d: Data) : Closeable {
     public fun doOutput(data: Int): Int = data
 }
 
-public open interface Closeable {
+public interface Closeable {
     open public fun close() {}
 }