[FIR] Add UNCHECKED_CAST

Regenerate diagnostics code

compiler/fir/analysis-tests/testData/resolveWithStdlib/intellij/UastPatterns.kt

@@ -30,9 +30,9 @@ fun uExpression(): UExpressionPattern.Capture<UExpression> = expressionCapture(U
 fun <T : UExpression> expressionCapture(clazz: Class<T>): UExpressionPattern.Capture<T> = UExpressionPattern.Capture(clazz)
 
 open class UElementPattern<T : UElement, Self : UElementPattern<T, Self>>(clazz: Class<T>) : ObjectPattern<T, Self>(clazz) {
-    fun filter(filter: (T) -> Boolean): Self = this as Self
+    fun filter(filter: (T) -> Boolean): Self = this <!UNCHECKED_CAST!>as Self<!>
 }
 
 open class UExpressionPattern<T : UExpression, Self : UExpressionPattern<T, Self>>(clazz: Class<T>) : UElementPattern<T, Self>(clazz) {
     open class Capture<T : UExpression>(clazz: Class<T>) : UExpressionPattern<T, Capture<T>>(clazz)
-}
+}

compiler/fir/analysis-tests/testData/resolveWithStdlib/listPlusAssign.kt

@@ -6,7 +6,7 @@ fun List<String>.modify() {
 }
 
 fun Any.modify() {
-    (<!VARIABLE_EXPECTED!>this as List<Int><!>) += 42
+    (<!VARIABLE_EXPECTED!>this <!UNCHECKED_CAST!>as List<Int><!><!>) += 42
 }
 
 operator fun <T> Set<T>.plusAssign(x: T) {}
@@ -17,5 +17,5 @@ fun Set<String>.modify() {
 }
 
 fun Any.modifySet() {
-    (this as Set<Int>) += 42
+    (this <!UNCHECKED_CAST!>as Set<Int><!>) += 42
 }