[Test] Adds a test case

Author: theblixguy

test/decl/var/property_wrappers.swift

@@ -1683,3 +1683,17 @@ final class SR_11478_C2 {
   @SR_11478_W class var bool2: Bool = true // expected-error {{class stored properties not supported in classes; did you mean 'static'?}}
   @SR_11478_W class final var bool3: Bool = true // expected-error {{class stored properties not supported in classes; did you mean 'static'?}}
 }
+
+// SR-11381
+
+@propertyWrapper
+struct SR_11381_W<T> {
+  init(wrappedValue: T) {}
+  var wrappedValue: T {
+    fatalError()
+  }
+}
+
+struct SR_11381_S {
+  @SR_11381_W var foo: Int = nil // expected-error {{'nil' is not compatible with expected argument type 'Int'}}
+}