FIR2IR: read extension function type attribute properly

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrBuiltIns.kt

@@ -37,6 +37,13 @@ class Fir2IrBuiltIns(
     internal fun flexibleNullabilityAnnotationConstructorCall(): IrConstructorCall? =
         flexibleNullabilityAnnotationSymbol?.toConstructorCall()
 
+    private val extensionFunctionTypeAnnotationSymbol by lazy {
+        annotationSymbolById(StandardClassIds.Annotations.ExtensionFunctionType)
+    }
+
+    internal fun extensionFunctionTypeAnnotationConstructorCall(): IrConstructorCall? =
+        extensionFunctionTypeAnnotationSymbol?.toConstructorCall()
+
     private fun annotationSymbolById(id: ClassId): IrClassSymbol? =
         provider?.getClassSymbolById(id) ?: session.symbolProvider.getClassLikeSymbolByClassId(id)?.toSymbol(
             session, classifierStorage, ConversionTypeContext.DEFAULT

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrTypeConverter.kt

@@ -5,6 +5,7 @@
 
 package org.jetbrains.kotlin.fir.backend
 
+import org.jetbrains.kotlin.fir.declarations.getAnnotationsByClassId
 import org.jetbrains.kotlin.fir.expressions.FirAnnotation
 import org.jetbrains.kotlin.fir.expressions.classId
 import org.jetbrains.kotlin.fir.languageVersionSettings
@@ -121,6 +122,13 @@ class Fir2IrTypeConverter(
                             typeAnnotations += it
                         }
                     }
+                    isExtensionFunctionType -> {
+                        if (annotations.getAnnotationsByClassId(StandardClassIds.Annotations.ExtensionFunctionType).isEmpty()) {
+                            builtIns.extensionFunctionTypeAnnotationConstructorCall()?.let {
+                                typeAnnotations += it
+                            }
+                        }
+                    }
                     hasFlexibleNullability -> {
                         builtIns.flexibleNullabilityAnnotationConstructorCall()?.let {
                             typeAnnotations += it