chore: import upstream snapshot with attribution

examples/direct-generic-vec.0

@@ -0,0 +1,29 @@
+type Vec<T: Type, static N: usize> {
+    len: usize = 0,
+    first: T,
+    items: [N]T,
+}
+
+enum TokenKind: u8 {
+    identifier,
+    eof,
+}
+
+enum NodeKind: u8 {
+    root,
+    literal,
+}
+
+export c fn main() -> u8 {
+    let bytes: Vec<u8, 2> = Vec { first: 3_u8, items: [1_u8, 2_u8] }
+    let tokens: Vec<TokenKind, 2> = Vec { first: TokenKind.identifier, items: [TokenKind.identifier, TokenKind.eof] }
+    let nodes: Vec<NodeKind, 2> = Vec { first: NodeKind.root, items: [NodeKind.root, NodeKind.literal] }
+    if bytes.first == 3_u8 {
+        if tokens.first == TokenKind.identifier {
+            if nodes.first == NodeKind.root {
+                return 61_u8
+            }
+        }
+    }
+    return 0_u8
+}