K1/K2: add a test to fix state of KT-55168

compiler/testData/diagnostics/testsWithStdLib/builderInference/buildListRemoveAddInBranches.kt

@@ -0,0 +1,8 @@
+// ISSUE: KT-55168
+fun foo(arg: Boolean) = buildList {
+    if (arg) <!TYPE_MISMATCH!>{
+        <!TYPE_MISMATCH!>removeLast()<!>
+    }<!> else {
+        add(42)
+    }
+}