Tests/PCLA: extend the test for KT-55168

#KT-55168 As Designed

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

@@ -6,3 +6,11 @@ fun foo(arg: Boolean) = buildList {
         add(<!ARGUMENT_TYPE_MISMATCH!>42<!>)
     }
 }
+
+fun bar(arg: Boolean) = buildList {
+    if (!arg) {
+        add(42)
+    } else {
+        removeLast()
+    }
+}

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

@@ -6,3 +6,11 @@ fun foo(arg: Boolean) = buildList {
         add(42)
     }
 }
+
+fun bar(arg: Boolean) = buildList {
+    if (!arg) {
+        add(42)
+    } else <!TYPE_MISMATCH!>{
+        <!TYPE_MISMATCH!>removeLast()<!>
+    }<!>
+}