feat(tvix): Re-enable language tests that needed a store

Now that we have access to a store in tests, we can enable the tests that needed a store.

Additionally, move the expected output files for disabled tests into the disabled folder.

Change-Id: I2492d49d43b93c7c9b0463e4d3d2855a5a51365d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1758
Tested-by: BuildkiteCI
Reviewed-by: glittershark <grfn@gws.fyi>

third_party/nix/src/tests/lang/disabled/eval-okay-context.nix

@@ -1,6 +0,0 @@
-let s = "foo ${builtins.substring 33 100 (baseNameOf "${./eval-okay-context.nix}")} bar";
-in
-  if s != "foo eval-okay-context.nix bar"
-  then abort "context not discarded"
-  else builtins.unsafeDiscardStringContext s
-

third_party/nix/src/tests/lang/eval-okay-context.exp

@@ -1 +0,0 @@
-"foo eval-okay-context.nix bar"

third_party/nix/src/tests/lang/evalstore-okay-context-introspection.nix

@@ -6,7 +6,7 @@ let
     outputs = [ "out" "foo" ];
   };
 
-  path = "${./eval-okay-context-introspection.nix}";
+  path = "${./evalstore-okay-context-introspection.nix}";
 
   desired-context = {
     "${builtins.unsafeDiscardStringContext path}" = {

third_party/nix/src/tests/lang/evalstore-okay-context.exp

@@ -0,0 +1 @@
+"foo evalstore-okay-context.nix bar"

third_party/nix/src/tests/lang/evalstore-okay-context.nix

@@ -0,0 +1,6 @@
+let s = "foo ${builtins.substring 33 100 (baseNameOf "${./evalstore-okay-context.nix}")} bar";
+in
+  if s != "foo evalstore-okay-context.nix bar"
+  then abort "context not discarded"
+  else builtins.unsafeDiscardStringContext s
+