Report warning on unused entities that can be renamed to _

Currently it's all about lambda parameters/destructuring entries

 #KT-14347 In Progress

compiler/testData/diagnostics/tests/inference/regressions/kt2283.kt

@@ -9,5 +9,5 @@ fun <A, B> Foo<A>.map(<!UNUSED_PARAMETER!>f<!>: (A) -> B): Foo<B> = object : Foo
 
 fun foo() {
     val l: Foo<String> = object : Foo<String> {}
-    val <!UNUSED_VARIABLE!>m<!>: Foo<String> = l.<!TYPE_INFERENCE_EXPECTED_TYPE_MISMATCH!>map { ppp -> 1 }<!>
-}
+    val <!UNUSED_VARIABLE!>m<!>: Foo<String> = l.<!TYPE_INFERENCE_EXPECTED_TYPE_MISMATCH!>map { <!UNUSED_PARAMETER!>ppp<!> -> 1 }<!>
+}

compiler/testData/diagnostics/tests/inference/regressions/kt2741.kt

@@ -7,5 +7,5 @@ fun <T> _arrayList(vararg <!UNUSED_PARAMETER!>values<!>: T) : List<T> = throw Ex
 class _Pair<A>(val a: A)
 
 fun test() {
-    _arrayList(_Pair(1))._sortBy { it -> <!UNRESOLVED_REFERENCE!>xxx<!> }
-}
+    _arrayList(_Pair(1))._sortBy { <!UNUSED_PARAMETER!>it<!> -> <!UNRESOLVED_REFERENCE!>xxx<!> }
+}

compiler/testData/diagnostics/tests/inference/regressions/kt2841.kt

@@ -9,7 +9,7 @@ public inline fun <T: Closeable, R> T.use1(block: (T)-> R) : R {
 
 fun main(args: Array<String>) {
     C().use1 {
-        w ->  // ERROR here
+        <!UNUSED_PARAMETER!>w<!> ->  // ERROR here
         <!UNRESOLVED_REFERENCE!>x<!>
     }
-}
+}

compiler/testData/diagnostics/tests/inference/regressions/kt3007.kt

@@ -8,7 +8,7 @@ enum class SomeEnum {
 
 // Doesn't work
 fun Iterable<Int>.some() {
-    this.fold(SomeEnum.FIRST, {res : SomeEnum, value ->
+    this.fold(SomeEnum.FIRST, {res : SomeEnum, <!UNUSED_PARAMETER!>value<!> ->
         if (res == SomeEnum.FIRST) SomeEnum.FIRST else SomeEnum.SECOND
     })
 }
@@ -19,7 +19,7 @@ fun tempFun() : SomeEnum {
 
 // Doesn't work
 fun Iterable<Int>.someSimpleWithFun() {
-    this.fold(SomeEnum.FIRST, {res : SomeEnum, value ->
+    this.fold(SomeEnum.FIRST, {<!UNUSED_PARAMETER!>res<!> : SomeEnum, <!UNUSED_PARAMETER!>value<!> ->
         tempFun()
     })
 }
@@ -27,17 +27,17 @@ fun Iterable<Int>.someSimpleWithFun() {
 
 // Works
 fun Iterable<Int>.someSimple() {
-    this.fold(SomeEnum.FIRST, {res : SomeEnum, value ->
+    this.fold(SomeEnum.FIRST, {<!UNUSED_PARAMETER!>res<!> : SomeEnum, <!UNUSED_PARAMETER!>value<!> ->
         SomeEnum.FIRST
     })
 }
 
 // Works
 fun Iterable<Int>.someInt() {
-    this.fold(0, {res : Int, value ->
+    this.fold(0, {res : Int, <!UNUSED_PARAMETER!>value<!> ->
         if (res == 0) 1 else 0
     })
 }
 
 //from standard library
-fun <T,R> Iterable<T>.fold(<!UNUSED_PARAMETER!>initial<!>: R, <!UNUSED_PARAMETER!>operation<!>: (R, T) -> R): R {<!NO_RETURN_IN_FUNCTION_WITH_BLOCK_BODY!>}<!>
+fun <T,R> Iterable<T>.fold(<!UNUSED_PARAMETER!>initial<!>: R, <!UNUSED_PARAMETER!>operation<!>: (R, T) -> R): R {<!NO_RETURN_IN_FUNCTION_WITH_BLOCK_BODY!>}<!>

compiler/testData/diagnostics/tests/inference/regressions/kt3150.kt

@@ -15,10 +15,10 @@ fun SomeTemplate.query(f: (i: Int) -> Unit) = f
 fun SomeTemplate.query1(f: (i: Int) -> Unit) = f
 
 fun test() {
-    val mapperFunction = { i: Int -> }
+    val mapperFunction = { <!UNUSED_PARAMETER!>i<!>: Int -> }
     SomeTemplate().query(mapperFunction)
 
     // TYPE_MISMATCH: Required Class<[ERROR: CANT_INFER]>, Found (kotlin.Int) -> Unit
-    SomeTemplate().query { i: Int -> }
-    SomeTemplate().query1 { i: Int -> }
+    SomeTemplate().query { <!UNUSED_PARAMETER!>i<!>: Int -> }
+    SomeTemplate().query1 { <!UNUSED_PARAMETER!>i<!>: Int -> }
 }