[FIR] Implement DEFINITELY_NON_NULLABLE_AS_REIFIED diagnostic

#KT-55646 Fixed

compiler/testData/diagnostics/tests/explicitDefinitelyNotNullableViaIntersection/reifiedArguments.fir.kt

@@ -1,8 +0,0 @@
-// SKIP_TXT
-// !LANGUAGE: +DefinitelyNonNullableTypes
-
-inline fun <reified T : Any> foo() {}
-
-inline fun <reified F> bar() {
-    foo<F & Any>()
-}

compiler/testData/diagnostics/tests/explicitDefinitelyNotNullableViaIntersection/reifiedArguments.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // SKIP_TXT
 // !LANGUAGE: +DefinitelyNonNullableTypes
 
@@ -6,3 +7,12 @@ inline fun <reified T : Any> foo() {}
 inline fun <reified F> bar() {
     foo<<!DEFINITELY_NON_NULLABLE_AS_REIFIED!>F & Any<!>>()
 }
+
+class KAnnotatedElement(val annotations: List<Any>)
+
+inline fun <reified T : Any> Iterable<*>.firstIsInstanceOrNull(): T? {
+    return null
+}
+
+private inline fun <reified T> KAnnotatedElement.findAnnotation(): T? =
+    annotations.firstIsInstanceOrNull()