test(tvix/eval): add some tests for recursive attribute sets

Change-Id: I6a4fbe6d5aa6d2ce223bf77330d6c0f512d4300d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6612
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI

tvix/eval/src/tests/tvix_tests/eval-okay-recursive-attrs-all-features.exp

@@ -0,0 +1 @@
+42

tvix/eval/src/tests/tvix_tests/eval-okay-recursive-attrs-all-features.nix

@@ -0,0 +1,13 @@
+let a = 1;
+in
+(rec {
+  inherit a;
+
+  b = {
+    c = a + 20;
+  };
+
+  inherit (b) c;
+
+  d = c * 2;
+}).d

tvix/eval/src/tests/tvix_tests/eval-okay-simple-recursive-attrs.exp

@@ -0,0 +1 @@
+42

tvix/eval/src/tests/tvix_tests/eval-okay-simple-recursive-attrs.nix

@@ -0,0 +1,4 @@
+(rec {
+  a = 21;
+  b = a * 2;
+}).b