[FIR] Make session & symbolProvider abstract classes

compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirSession.kt

@@ -9,17 +9,24 @@ import org.jetbrains.kotlin.analyzer.ModuleInfo
 import org.jetbrains.kotlin.utils.Jsr305State
 import kotlin.reflect.KClass
 
-interface FirSession {
-    val moduleInfo: ModuleInfo?
-
-    val sessionProvider: FirSessionProvider? get() = null
+abstract class FirSession(val sessionProvider: FirSessionProvider?) {
+    open val moduleInfo: ModuleInfo? get() = null
 
     val jsr305State: Jsr305State? get() = null
 
-    val components: Map<KClass<*>, Any>
+
+    val components: MutableMap<KClass<*>, Any> = mutableMapOf()
+
+    var _firSymbolProvider: Any? = null
+
 
     fun <T : Any> getService(kclass: KClass<T>): T =
         components[kclass] as T
+
+    protected fun <T : Any> registerComponent(tClass: KClass<T>, t: T) {
+        assert(tClass !in components) { "Already registered component" }
+        components[tClass] = t
+    }
 }
 
 interface FirSessionProvider {

compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirSessionBase.kt

@@ -5,18 +5,7 @@
 
 package org.jetbrains.kotlin.fir
 
-import org.jetbrains.kotlin.analyzer.ModuleInfo
-import kotlin.reflect.KClass
 
-abstract class FirSessionBase : FirSession {
-    override val components: MutableMap<KClass<*>, Any> = mutableMapOf()
-
-    override val moduleInfo: ModuleInfo?
-        get() = null
-
-    protected fun <T : Any> registerComponent(tClass: KClass<T>, t: T) {
-        assert(tClass !in components) { "Already registered component" }
-        components[tClass] = t
-    }
+abstract class FirSessionBase(sessionProvider: FirSessionProvider?) : FirSession(sessionProvider) {
 }