Add feature const_option

src/test/ui/consts/const-option.rs

@@ -0,0 +1,14 @@
+// run-pass
+
+#![feature(const_option)]
+
+const X: Option<i32> = Some(32);
+const Y: Option<&i32> = X.as_ref();
+
+const IS_SOME: bool = X.is_some();
+const IS_NONE: bool = Y.is_none();
+
+fn main() {
+    assert!(IS_SOME);
+    assert!(!IS_NONE)
+}