FIR: provide super-type as the self-type for anonymous objects

This commit is a temporary approximation useful before we have
symbols for local classes & objects

compiler/fir/resolve/testData/resolve/expresssions/localImplicitBodies.txt

@@ -1,7 +1,7 @@
 FILE: localImplicitBodies.kt
     public final fun foo(): R|kotlin/Unit| {
-        lval x: <ERROR TYPE REF: No result type for initializer> = object : R|kotlin/Any| {
-            private constructor(): R|class error: Symbol not found, for `<no name provided>`| {
+        lval x: R|kotlin/Any| = object : R|kotlin/Any| {
+            private constructor(): R|kotlin/Any| {
                 super<R|kotlin/Any|>()
             }