Ensure that a failure passes for 'simple_literals2.t' which checks for a failing to coerce due to incompatible types

.github/workflows/d.yml

@@ -207,8 +207,16 @@ jobs:
         
       - name: Simple literals
         run: ./tlang typecheck source/tlang/testing/simple_literals.t
-      - name: Simple literals 2
-        run: ./tlang typecheck source/tlang/testing/simple_literals2.t
+      - name: Simple literals 2 (uncoercible)
+        run: |
+          set e+
+          ./tlang typecheck source/tlang/testing/simple_literals2.t
+          if [ $? = 255 ]
+          then
+              exit 0
+          else
+              exit 1
+          fi
       - name: Simple literals 3
         run: ./tlang typecheck source/tlang/testing/simple_literals3.t
       - name: Simple literals 4