Add a jit test for multiple evaluation from scratch file

unison-src/builtin-tests/jit-tests.md

@@ -103,3 +103,17 @@ to `Tests.check` and `Tests.checkEqual`).
 ```ucm
 .> run.native tests.jit.only
 ```
+
+```unison
+foo = do
+  go : Nat ->{Exception} ()
+  go = cases
+    0 -> ()
+    n -> go (decrement n)
+  go 1000
+```
+
+```ucm
+.> run.native foo
+.> run.native foo
+```

unison-src/builtin-tests/jit-tests.output.md

@@ -17,3 +17,35 @@ to `Tests.check` and `Tests.checkEqual`).
   ()
 
 ```
+```unison
+foo = do
+  go : Nat ->{Exception} ()
+  go = cases
+    0 -> ()
+    n -> go (decrement n)
+  go 1000
+```
+
+```ucm
+
+  Loading changes detected in scratch.u.
+
+  I found and typechecked these definitions in scratch.u. If you
+  do an `add` or `update`, here's how your codebase would
+  change:
+  
+    ⍟ These new definitions are ok to `add`:
+    
+      foo : '{Exception} ()
+
+```
+```ucm
+.> run.native foo
+
+  ()
+
+.> run.native foo
+
+  ()
+
+```