[FIR] Ensure KT-50293 is no longer a problem

PCLA-related changes led to this change in
behavior. In K1 an explicit cast was needed
to prevent ORA, but now in K2 this code
is green without casts.

^KT-50293 Obsolete

compiler/testData/diagnostics/tests/inference/builderInference/kt49829_noCast.fir.kt

@@ -0,0 +1,12 @@
+// WITH_STDLIB
+// ISSUE: KT-50293
+
+fun main() {
+    val list = buildList {
+        add("one")
+        add("two")
+
+        val secondParameter = get(1)
+        println(secondParameter)
+    }
+}

compiler/testData/diagnostics/tests/inference/builderInference/kt49829_noCast.kt

@@ -0,0 +1,12 @@
+// WITH_STDLIB
+// ISSUE: KT-50293
+
+fun main() {
+    val list = buildList {
+        add("one")
+        add("two")
+
+        val secondParameter = get(1)
+        <!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE, OVERLOAD_RESOLUTION_AMBIGUITY, OVERLOAD_RESOLUTION_AMBIGUITY_BECAUSE_OF_STUB_TYPES!>println<!>(<!STUB_TYPE_IN_ARGUMENT_CAUSES_AMBIGUITY!>secondParameter<!>)
+    }
+}