FIR: consider Java default constructors as primary ones

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/JavaSymbolProvider.kt

@@ -210,11 +210,14 @@ class JavaSymbolProvider(
                     val javaClassDeclaredConstructors = javaClass.constructors
                     val constructorId = CallableId(classId.packageFqName, classId.relativeClassName, classId.shortClassName)
 
-                    fun addJavaConstructor(visibility: Visibility = this.visibility): FirJavaConstructor {
+                    fun addJavaConstructor(
+                        visibility: Visibility = this.visibility,
+                        isPrimary: Boolean = false
+                    ): FirJavaConstructor {
                         val constructorSymbol = FirConstructorSymbol(constructorId)
                         val classTypeParameters = javaClass.typeParameters.convertTypeParameters(javaTypeParameterStack)
                         val firJavaConstructor = FirJavaConstructor(
-                            this@JavaSymbolProvider.session, constructorSymbol, visibility,
+                            this@JavaSymbolProvider.session, constructorSymbol, visibility, isPrimary,
                             FirResolvedTypeRefImpl(
                                 this@JavaSymbolProvider.session, null,
                                 firSymbol.constructType(
@@ -230,7 +233,7 @@ class JavaSymbolProvider(
                     }
 
                     if (javaClassDeclaredConstructors.isEmpty() && javaClass.classKind == ClassKind.CLASS) {
-                        addJavaConstructor()
+                        addJavaConstructor(isPrimary = true)
                     }
                     for (javaConstructor in javaClassDeclaredConstructors) {
                         addJavaConstructor(javaConstructor.visibility).apply {

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/declarations/FirJavaConstructor.kt

@@ -21,6 +21,7 @@ class FirJavaConstructor(
     session: FirSession,
     override val symbol: FirConstructorSymbol,
     visibility: Visibility,
+    override val isPrimary: Boolean,
     delegatedSelfTypeRef: FirTypeRef
 ) : FirAbstractCallableMember<FirConstructor>(
     session,

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/scopes/JavaClassEnhancementScope.kt

@@ -180,12 +180,26 @@ class JavaClassEnhancementScope(
             }
         }
         val function: FirMemberFunction<*> = when (firMethod) {
-            is FirJavaConstructor -> FirConstructorImpl(
-                this@JavaClassEnhancementScope.session, null, FirConstructorSymbol(methodId),
-                newReceiverTypeRef, newReturnTypeRef
-            ).apply {
-                this.valueParameters += newValueParameters
-                this.typeParameters += firMethod.typeParameters
+            is FirJavaConstructor -> {
+                val symbol = FirConstructorSymbol(methodId)
+                if (firMethod.isPrimary) {
+                    FirPrimaryConstructorImpl(
+                        this@JavaClassEnhancementScope.session, null, symbol,
+                        firMethod.visibility,
+                        isExpect = false,
+                        isActual = false,
+                        delegatedSelfTypeRef = newReturnTypeRef,
+                        delegatedConstructor = null
+                    )
+                } else {
+                    FirConstructorImpl(
+                        this@JavaClassEnhancementScope.session, null, symbol,
+                        newReceiverTypeRef, newReturnTypeRef
+                    )
+                }.apply {
+                    this.valueParameters += newValueParameters
+                    this.typeParameters += firMethod.typeParameters
+                }
             }
             else -> FirMemberFunctionImpl(
                 this@JavaClassEnhancementScope.session, null,