Vendor dependencies

Let's see how I like this workflow.

vendor/unicode-ident/tests/roaring/mod.rs

@@ -0,0 +1,21 @@
+use roaring::RoaringBitmap;
+
+pub fn xid_start_bitmap() -> RoaringBitmap {
+    let mut bitmap = RoaringBitmap::new();
+    for ch in '\0'..=char::MAX {
+        if unicode_ident::is_xid_start(ch) {
+            bitmap.insert(ch as u32);
+        }
+    }
+    bitmap
+}
+
+pub fn xid_continue_bitmap() -> RoaringBitmap {
+    let mut bitmap = RoaringBitmap::new();
+    for ch in '\0'..=char::MAX {
+        if unicode_ident::is_xid_continue(ch) {
+            bitmap.insert(ch as u32);
+        }
+    }
+    bitmap
+}