Dropped index from DeserializedSourceFile as it is no longer needed

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/LegacyDescriptorUtils.kt

@@ -56,7 +56,7 @@ val ModuleDescriptor.isForwardDeclarationModule get() =
 private fun sourceByIndex(descriptor: CallableMemberDescriptor, index: Int): SourceFile {
     val fragment = descriptor.findPackage() as KlibMetadataDeserializedPackageFragment
     val fileName = fragment.proto.strings.stringList[index]
-    return DeserializedSourceFile(fileName, index, descriptor.module.kotlinLibrary)
+    return DeserializedSourceFile(fileName, descriptor.module.kotlinLibrary)
 }
 
 fun CallableMemberDescriptor.findSourceFile(): SourceFile {

compiler/util-klib-metadata/src/org/jetbrains/kotlin/library/metadata/DeserializedSourceFile.kt

@@ -8,15 +8,15 @@ import org.jetbrains.kotlin.descriptors.SourceFile
 import org.jetbrains.kotlin.library.KotlinLibrary
 
 class DeserializedSourceFile(
-    val name_: String, val index: Int, val library: KotlinLibrary
+    val name_: String, val library: KotlinLibrary
 ) : SourceFile {
     override fun getName(): String? = name_
 
     override fun equals(other: Any?): Boolean {
-        return other is DeserializedSourceFile && library == other.library && index == other.index
+        return other is DeserializedSourceFile && library == other.library && name == other.name
     }
 
     override fun hashCode(): Int {
-        return library.hashCode() xor index
+        return library.hashCode() xor name.hashCode()
     }
 }