make UI tests that use --test work on panic=abort targets

using a second revision that also passes `-Zpanic_abort_test`

the first revision, which does not use the `-Z` flag, is configured to
only run on targets that support unwinding

fixes #135819

Author: japaric

tests/ui/macros/rfc-2011-nicer-assert-messages/assert-with-custom-errors-does-not-create-unnecessary-code.rs

@@ -1,4 +1,10 @@
-//@ compile-flags: --test
+//@ revisions: can_unwind
+//@ [can_unwind] compile-flags: --test
+//@ [can_unwind] needs-unwind
+//
+//@ revisions: cannot_unwind
+//@ [cannot_unwind] compile-flags: --test -Zpanic_abort_tests
+//
 //@ run-pass
 
 #![feature(core_intrinsics, generic_assert)]

tests/ui/macros/rfc-2011-nicer-assert-messages/feature-gate-generic_assert.rs

@@ -1,4 +1,10 @@
-//@ compile-flags: --test
+//@ revisions: can_unwind
+//@ [can_unwind] compile-flags: --test
+//@ [can_unwind] needs-unwind
+//
+//@ revisions: cannot_unwind
+//@ [cannot_unwind] compile-flags: --test -Zpanic_abort_tests
+//
 // ignore-tidy-linelength
 //@ run-pass