[FIR] Use class scope to get constructors for redeclaration check

#KT-60793 Fixed

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/FirConflictsHelpers.kt

@@ -129,8 +129,10 @@ private fun groupTopLevelByName(declarations: List<FirDeclaration>): Map<Name, D
  * Collects FirDeclarations for further analysis.
  */
 class FirDeclarationInspector(
-    private val session: FirSession,
+    private val context: CheckerContext,
 ) {
+    private val session: FirSession get() = context.sessionHolder.session
+
     val declarationConflictingSymbols: HashMap<FirDeclaration, SmartSet<FirBasedSymbol<*>>> = hashMapOf()
 
     fun collectClassMembers(klass: FirRegularClass) {
@@ -184,6 +186,7 @@ class FirDeclarationInspector(
      * | constructors of classes | X               |              |            |            |                     |
      * | properties              |                 |              | X          | X          | X                   |
      */
+    @OptIn(SymbolInternals::class)
     @Suppress("GrazieInspection")
     fun collectTopLevel(file: FirFile, packageMemberScope: FirPackageMemberScope) {
 
@@ -224,11 +227,10 @@ class FirDeclarationInspector(
                     if (conflictingSymbol.classKind == ClassKind.OBJECT || conflictingSymbol.classKind == ClassKind.ENUM_ENTRY) return
 
                     conflictingSymbol.lazyResolveToPhase(FirResolvePhase.STATUS)
-                    @OptIn(SymbolInternals::class)
                     val classWithSameName = conflictingSymbol.fir
-                    classWithSameName.declarations.filterIsInstance<FirConstructor>().forEach { constructor ->
-                        val ctorRepresentation = FirRedeclarationPresenter.represent(constructor, classWithSameName)
-                        collect(group.simpleFunctions, conflictingSymbol = constructor.symbol, conflictingPresentation = ctorRepresentation)
+                    classWithSameName.unsubstitutedScope(context).processDeclaredConstructors { constructor ->
+                        val ctorRepresentation = FirRedeclarationPresenter.represent(constructor.fir, classWithSameName)
+                        collect(group.simpleFunctions, conflictingSymbol = constructor, conflictingPresentation = ctorRepresentation)
                     }
                 }
             }

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirConflictsDeclarationChecker.kt

@@ -27,7 +27,7 @@ object FirConflictsDeclarationChecker : FirBasicDeclarationChecker() {
     override fun check(declaration: FirDeclaration, context: CheckerContext, reporter: DiagnosticReporter) {
         when (declaration) {
             is FirFile -> {
-                val inspector = FirDeclarationInspector(context.sessionHolder.session)
+                val inspector = FirDeclarationInspector(context)
                 checkFile(declaration, inspector, context)
                 reportConflicts(reporter, context, inspector.declarationConflictingSymbols)
             }
@@ -35,7 +35,7 @@ object FirConflictsDeclarationChecker : FirBasicDeclarationChecker() {
                 if (declaration.source?.kind !is KtFakeSourceElementKind) {
                     checkForLocalRedeclarations(declaration.typeParameters, context, reporter)
                 }
-                val inspector = FirDeclarationInspector(context.sessionHolder.session)
+                val inspector = FirDeclarationInspector(context)
                 inspector.collectClassMembers(declaration)
                 reportConflicts(reporter, context, inspector.declarationConflictingSymbols)
             }

compiler/testData/diagnostics/tests/overload/ConstructorVsFunOverload.fir.kt

@@ -1,5 +1,13 @@
 // constructor vs. fun overload
 
+// FILE: J.java
+package constructorVsFun;
+
+public class J {
+    public J(String s) {}
+}
+
+// FILE: test.kt
 package constructorVsFun
 
 class a<!CONFLICTING_OVERLOADS!>()<!> { }
@@ -26,4 +34,6 @@ class Rtyu {
     companion object {
         class ololo() { }
     }
-}
+}
+
+<!CONFLICTING_OVERLOADS!>fun J(s: String)<!> { }

compiler/testData/diagnostics/tests/overload/ConstructorVsFunOverload.kt

@@ -1,5 +1,13 @@
 // constructor vs. fun overload
 
+// FILE: J.java
+package constructorVsFun;
+
+public class J {
+    public J(String s) {}
+}
+
+// FILE: test.kt
 package constructorVsFun
 
 class a<!CONFLICTING_OVERLOADS!>()<!> { }
@@ -26,4 +34,6 @@ class Rtyu {
     companion object {
         class ololo() { }
     }
-}
+}
+
+fun J(s: String) { }

compiler/testData/diagnostics/tests/overload/ConstructorVsFunOverload.txt

@@ -1,8 +1,16 @@
 package
 
 package constructorVsFun {
+    public fun J(/*0*/ s: kotlin.String): kotlin.Unit
     public fun a(): kotlin.Int
 
+    public open class J {
+        public constructor J(/*0*/ s: kotlin.String!)
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+
     public final class Rtyu {
         public constructor Rtyu()
         public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean