test: Add tests for issue #452

Author: brson

src/test/run-fail/expr-alt-fail-fn.rs

@@ -0,0 +1,19 @@
+// error-pattern:explicit failure
+
+fn f() -> ! { fail }
+
+fn g() -> int {
+  auto x = alt (true) {
+    case (true) {
+      f()
+    }
+    case (false) {
+      10
+    }
+  };
+  ret x;
+}
+
+fn main() {
+  g();
+}

src/test/run-fail/expr-if-fail-fn.rs

@@ -0,0 +1,16 @@
+// error-pattern:explicit failure
+
+fn f() -> ! { fail }
+
+fn g() -> int {
+  auto x = if (true) {
+    f()
+  } else {
+    10
+  };
+  ret x;
+}
+
+fn main() {
+  g();
+}