feat(tvix/eval): Implement builtins.genList

Change-Id: Iabe28656229f508226b244d81382e517961eb3cf
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6901
Autosubmit: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>

tvix/eval/src/value/mod.rs

@@ -359,6 +359,12 @@ impl Display for Value {
     }
 }
 
+impl From<i64> for Value {
+    fn from(i: i64) -> Self {
+        Self::Integer(i)
+    }
+}
+
 fn type_error(expected: &'static str, actual: &Value) -> ErrorKind {
     ErrorKind::TypeError {
         expected,