lifetimes: Reuse heap in another test

Summary:
`Eq` and `PartialEq` are only implemented for two `Value<'v>`s, not for one `Value<'v1>` and one `Value<'v2>`, but this test was comparing values coming from two different heaps.

We could actually consider changing the eq behavior to allow this, but that would in turn require changing the signature on all `StarlarkValue`s and this doesn't seem like good motivation yet.

Reviewed By: ship-it-ship-it

Differential Revision: D90475052

fbshipit-source-id: 4b3c8b70e5ae1b6db37c55f39262c39efd44b147

Author: JakobDegen

starlark/src/assert/assert.rs

@@ -572,13 +572,14 @@ impl<'a> Assert<'a> {
     /// ```
     pub fn eq(&self, lhs: &str, rhs: &str) {
         self.with_gc(|gc| {
-            Module::with_temp_heap(|lhs_m| {
-                Module::with_temp_heap(|rhs_m| {
-                    let lhs_v = self.execute_unwrap("eq", "lhs.bzl", lhs, &lhs_m, gc);
-                    let rhs_v = self.execute_unwrap("eq", "rhs.bzl", rhs, &rhs_m, gc);
-                    if lhs_v != rhs_v {
-                        panic!(
-                            "starlark::assert::eq, values differ!
+            Heap::temp(|heap| {
+                let lhs_m = Module::with_heap(heap);
+                let rhs_m = Module::with_heap(heap);
+                let lhs_v = self.execute_unwrap("eq", "lhs.bzl", lhs, &lhs_m, gc);
+                let rhs_v = self.execute_unwrap("eq", "rhs.bzl", rhs, &rhs_m, gc);
+                if lhs_v != rhs_v {
+                    panic!(
+                        "starlark::assert::eq, values differ!
 Code 1:
 {lhs}
 Code 2:
@@ -587,9 +588,8 @@ Value 1:
 {lhs_v}
 Value 2
 {rhs_v}"
-                        );
-                    }
-                })
+                    );
+                }
             })
         })
     }