Refine the semantics of domain callbacks.

This PR (#11213) addresses issues pointed out in #11176 and #11178. It
makes the following changes:

* `Domain.at_exit` is now domain-local.
* `Domain.at_exit` also used to ignore exceptions. Now, these exceptions
  are surfaced as the result of domain execution (similar to how
  `Stdlib.at_exit` works).
* `Domain.at_startup` is renamed to `Domain.at_each_spawn`.
* `Domain.at_first_spawn` is renamed to `Domain.before_first_spawn`.
* `Domain.before_first_spawn` and `Domain.at_each_spawn` run the
  callbacks in FIFO order (as requested in #11178).

The PR also adds tests to the test suite.

1 files changed, 6 insertions, 6 deletions

diff --git a/testsuite/tests/generalized-open/gpr1506.ml b/testsuite/tests/generalized-open/gpr1506.ml
index bd72ed302f..f6919c78f4 100644
--- a/testsuite/tests/generalized-open/gpr1506.ml
+++ b/testsuite/tests/generalized-open/gpr1506.ml
@@ -103,9 +103,9 @@ include struct open struct type t = T end let x = T end
 Line 1, characters 15-41:
 1 | include struct open struct type t = T end let x = T end
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^
-Error: The type t/337 introduced by this open appears in the signature
+Error: The type t/338 introduced by this open appears in the signature
        Line 1, characters 46-47:
-         The value x has no valid type if t/337 is hidden
+         The value x has no valid type if t/338 is hidden
 |}];;
 
 module A = struct
@@ -123,9 +123,9 @@ Lines 3-6, characters 4-7:
 4 |       type t = T
 5 |       let x = T
 6 |     end
-Error: The type t/342 introduced by this open appears in the signature
+Error: The type t/343 introduced by this open appears in the signature
        Line 7, characters 8-9:
-         The value y has no valid type if t/342 is hidden
+         The value y has no valid type if t/343 is hidden
 |}];;
 
 module A = struct
@@ -142,9 +142,9 @@ Lines 3-5, characters 4-7:
 3 | ....open struct
 4 |       type t = T
 5 |     end
-Error: The type t/347 introduced by this open appears in the signature
+Error: The type t/348 introduced by this open appears in the signature
        Line 6, characters 8-9:
-         The value y has no valid type if t/347 is hidden
+         The value y has no valid type if t/348 is hidden
 |}]
 
 (* It was decided to not allow this anymore. *)