KT-62071 [AA] Do not throw error from getScopeContextForPosition when implicitScope of receiver value is null

`implicitScope` can be `null`
in case when the implicit receiver resides in a user-defined `kotlin.*`
package, but the user have not yet allowed this with compiler argument
directive.

In this case,
we don't want the IDE to crush and show exceptions - the `kotlin`
package would be highlighted by the compiler diagnostics and other
resolve problems, and that would be enough

^KT-62071 Fixed

compiler/fir/semantics/src/org/jetbrains/kotlin/fir/declarations/ImplicitReceiverUtils.kt

@@ -282,13 +282,14 @@ class FirTowerDataElement(
     private fun ImplicitReceiverValue<*>.getImplicitScope(
         processTypeScope: FirTypeScope.(ConeKotlinType) -> FirTypeScope,
     ): FirScope {
-        return when (val type = type.fullyExpandedType(useSiteSession)) {
-            is ConeErrorType,
-            is ConeStubType -> FirTypeScope.Empty
-            else -> implicitScope?.processTypeScope(type) ?: errorWithAttachment("Scope for type ${type::class.simpleName} is null") {
-                withConeTypeEntry("type", type)
-            }
-        }
+        // N.B.: implicitScope == null when the type sits in a user-defined 'kotlin' package,
+        // but there is no '-Xallow-kotlin-package' compiler argument provided
+        val implicitScope = implicitScope ?: return FirTypeScope.Empty
+
+        val type = type.fullyExpandedType(useSiteSession)
+        if (type is ConeErrorType || type is ConeStubType) return FirTypeScope.Empty
+
+        return implicitScope.processTypeScope(type)
     }
 }