Psi2Ir: fix usage of flexible vararg type after approximation

This only affects JVM IR, and this is similar to how this was done in
the old JVM backend in `CallBasedArgumentGenerator.generateVararg`.

 #KT-52146 Fixed

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java

@@ -48371,6 +48371,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/vararg/kt46092.kt");
         }
 
+        @Test
+        @TestMetadata("kt52146_samWithSelfTypeAndStarProjection.kt")
+        public void testKt52146_samWithSelfTypeAndStarProjection() throws Exception {
+            runTest("compiler/testData/codegen/box/vararg/kt52146_samWithSelfTypeAndStarProjection.kt");
+        }
+
         @Test
         @TestMetadata("kt581.kt")
         public void testKt581() throws Exception {