[FIR] Implement FUNCTION_EXPECTED

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/diagnostics/KtFirDataClassConverters.kt

@@ -327,6 +327,14 @@ internal val KT_DIAGNOSTIC_CONVERTER = KtDiagnosticConverterBuilder.buildConvert
             token,
         )
     }
+    add(FirErrors.FUNCTION_EXPECTED) { firDiagnostic ->
+        FunctionExpectedImpl(
+            firDiagnostic.a,
+            firSymbolBuilder.typeBuilder.buildKtType(firDiagnostic.b),
+            firDiagnostic as FirPsiDiagnostic,
+            token,
+        )
+    }
     add(FirErrors.SUPER_IS_NOT_AN_EXPRESSION) { firDiagnostic ->
         SuperIsNotAnExpressionImpl(
             firDiagnostic as FirPsiDiagnostic,

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/diagnostics/KtFirDiagnostics.kt

@@ -257,6 +257,12 @@ sealed class KtFirDiagnostic<PSI : PsiElement> : KtDiagnosticWithPsi<PSI> {
         override val diagnosticClass get() = NoReceiverAllowed::class
     }
 
+    abstract class FunctionExpected : KtFirDiagnostic<PsiElement>() {
+        override val diagnosticClass get() = FunctionExpected::class
+        abstract val expression: String
+        abstract val type: KtType
+    }
+
     abstract class SuperIsNotAnExpression : KtFirDiagnostic<PsiElement>() {
         override val diagnosticClass get() = SuperIsNotAnExpression::class
     }

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/diagnostics/KtFirDiagnosticsImpl.kt

@@ -381,6 +381,15 @@ internal class NoReceiverAllowedImpl(
     override val firDiagnostic: FirPsiDiagnostic by weakRef(firDiagnostic)
 }
 
+internal class FunctionExpectedImpl(
+    override val expression: String,
+    override val type: KtType,
+    firDiagnostic: FirPsiDiagnostic,
+    override val token: ValidityToken,
+) : KtFirDiagnostic.FunctionExpected(), KtAbstractFirDiagnostic<PsiElement> {
+    override val firDiagnostic: FirPsiDiagnostic by weakRef(firDiagnostic)
+}
+
 internal class SuperIsNotAnExpressionImpl(
     firDiagnostic: FirPsiDiagnostic,
     override val token: ValidityToken,