K2: add test to confirm behavior described in KT-62918

#KT-62918 Obsolete
Related to: KT-60086, KT-59920

compiler/testData/diagnostics/tests/exposed/ambiguousAnonymousExposed.fir.kt

@@ -0,0 +1,14 @@
+// ISSUE: KT-62918
+// FIR_DUMP
+
+class My<T>(val value: T)
+interface I1
+interface I2
+
+<!AMBIGUOUS_ANONYMOUS_TYPE_INFERRED!>fun foo()<!> = My(object : I1, I2 {})
+
+fun fooFoo(): My<I1> = My(object : I1, I2 {})
+
+<!AMBIGUOUS_ANONYMOUS_TYPE_INFERRED!>internal fun bar()<!> = My(object : I1, I2 {})
+
+private fun baz() = My(object : I1, I2 {})