KT-6671 Report unused constructor parameters

#KT-6671 fixed

idea/testData/checker/Constructors.kt

@@ -14,7 +14,7 @@ class NoPC {
 class WithPC0() {
 }
 
-class WithPC1(a : Int) {
+class WithPC1(<warning>a</warning> : Int) {
 }
 
 
@@ -22,7 +22,7 @@ class Foo() : <error>WithPC0</error>(), <error>this</error>() {
 
 }
 
-class WithCPI_Dup(x : Int) {
+class WithCPI_Dup(<warning>x</warning> : Int) {
   <error>var x : Int</error>
 }