[FIR] Use proper directOverriddenFunctions fun in FirNativeThrowsChecker

Fix false positive `INCOMPATIBLE_THROWS_OVERRIDE`

^KT-65105 Fixed

Merge-request: KT-MR-14937
Merged-by: Ivan Kochurkin <Ivan.Kochurkin@jetbrains.com>

compiler/testData/diagnostics/nativeTests/throws.fir.kt

@@ -1,3 +1,5 @@
+// ISSUE: KT-65105
+
 // FILE: kotlin.kt
 package kotlin
 
@@ -376,3 +378,13 @@ typealias ThrowableAlias = Throwable
 
 @Throws(ThrowableAlias::class)
 suspend fun suspendThrowsThrowableTypealias() {}
+
+interface Foo<T> {
+    @Throws(IllegalArgumentException::class)
+    public fun f(data: T) {}
+}
+
+class Bar<K> : Foo<K> {
+    @Throws(IllegalArgumentException::class)
+    override fun f(data: K) {}
+}

compiler/testData/diagnostics/nativeTests/throws.kt

@@ -1,3 +1,5 @@
+// ISSUE: KT-65105
+
 // FILE: kotlin.kt
 package kotlin
 
@@ -376,3 +378,13 @@ typealias ThrowableAlias = Throwable
 
 @Throws(ThrowableAlias::class)
 suspend fun suspendThrowsThrowableTypealias() {}
+
+interface Foo<T> {
+    @Throws(IllegalArgumentException::class)
+    public fun f(data: T) {}
+}
+
+class Bar<K> : Foo<K> {
+    @Throws(IllegalArgumentException::class)
+    override fun f(data: K) {}
+}

compiler/testData/diagnostics/nativeTests/throws.txt

@@ -47,6 +47,14 @@ package
 @kotlin.Throws(exceptionClasses = {}) public fun throwsUnresolved(): kotlin.Unit
 public fun withLocalClass(): kotlin.Unit
 
+public final class Bar</*0*/ K> : Foo<K> {
+    public constructor Bar</*0*/ K>()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    @kotlin.Throws(exceptionClasses = {kotlin.IllegalArgumentException::class}) public open override /*1*/ fun f(/*0*/ data: K): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
 public interface Base0 {
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public abstract fun foo(): kotlin.Unit
@@ -152,6 +160,13 @@ public final class Exception3 : kotlin.Throwable {
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }
 
+public interface Foo</*0*/ T> {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    @kotlin.Throws(exceptionClasses = {kotlin.IllegalArgumentException::class}) public open fun f(/*0*/ data: T): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
 public final class HasThrowsWithEmptyListOnOverride : Base1 {
     public constructor HasThrowsWithEmptyListOnOverride()
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean