Support getContainer for the synthetic it value parameter

Also fixed incorrect KtSymbolOrigin:
it was SOURCE instead of SOURCE_MEMBER_GENERATED

idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/symbols/KtSymbol.kt

@@ -53,6 +53,7 @@ enum class KtSymbolOrigin {
      * Declaration which do not have it's PSI source and was generated, they are:
      * For data classes the `copy`, `component{N}`, `toString`, `equals`, `hashCode` functions are generated
      * For enum classes the `valueOf` & `values` functions are generated
+     * For lambda the `it` property is generated
      */
     SOURCE_MEMBER_GENERATED,
 

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/fir/FirIdeDeserializedDeclarationSourceProvider.kt

@@ -139,7 +139,7 @@ object FirIdeDeserializedDeclarationSourceProvider {
 
 private fun KtElement.isCompiled(): Boolean = containingKtFile.isCompiled
 
-private val allowedFakeElementKinds = setOf(FirFakeSourceElementKind.PropertyFromParameter)
+private val allowedFakeElementKinds = setOf(FirFakeSourceElementKind.PropertyFromParameter, FirFakeSourceElementKind.ItLambdaParameter)
 
 private fun FirElement.getAllowedPsi() = when (val source = source) {
     null -> null

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/symbols/KtFirSymbol.kt

@@ -26,6 +26,7 @@ private tailrec fun FirDeclaration.ktSymbolOrigin(): KtSymbolOrigin = when (orig
     FirDeclarationOrigin.Source -> {
         if (source?.kind == FirFakeSourceElementKind.DataClassGeneratedMembers
             || source?.kind == FirFakeSourceElementKind.EnumGeneratedDeclaration
+            || source?.kind == FirFakeSourceElementKind.ItLambdaParameter
         ) {
             KtSymbolOrigin.SOURCE_MEMBER_GENERATED
         } else KtSymbolOrigin.SOURCE