xfail(reify): examples/0614-comptime-reify-enum — reify a flat enum

REIFY Phase 0.1. Add the end-to-end Phase-0 example: reify a flat enum
(value: i64, closed) from a TypeInfo literal, construct E.value(3) /
E.closed, and match both arms. Seed an empty expected/*.exit marker.

RED by design (reify still bails -> "unparseable expected exit"); the
next commit (0.2) implements reify and turns it green. Satisfies the
no-commit-both-adds-a-test-and-passes cadence.

examples/0614-comptime-reify-enum.sx

@@ -0,0 +1,29 @@
+// REIFY Phase 0: mint a NEW nominal enum from a `TypeInfo` value at comptime,
+// then construct one of its variants and match on it — exercising that a
+// reify'd enum (with NO backing AST decl) flows through enum codegen unmodified
+// (layout / construct / match), Contract 2.
+//
+// The enum has two variants: `value` carrying an i64 payload, and `closed` with
+// no payload (`payload = void`).
+#import "modules/std.sx";
+#import "modules/std/meta.sx";
+
+E :: reify(.`enum(.{ variants = .[
+    EnumVariant.{ name = "value",  payload = i64  },
+    EnumVariant.{ name = "closed", payload = void },
+] }));
+
+main :: () -> i32 {
+    e := E.value(3);
+    if e == {
+        case .value: (v) { print("value {}\n", v); }
+        case .closed: { print("closed\n"); }
+    }
+
+    c := E.closed;
+    if c == {
+        case .value: (v) { print("value {}\n", v); }
+        case .closed: { print("closed\n"); }
+    }
+    return 0;
+}