Ignore fuchsia tests implicitly relying on a signal upon abort

Both test-panic-abort-nocapture.rs and test-panic-abort.rs assert the
stderr output of the test. On Fuchsia, if a test fails an assertion,
this output will contain a line noting the process returned the code
-1028 (ZX_TASK_RETCODE_EXCEPTION_KILL). But the asserted stderr output
lacks this note. Presumably this is because other platforms implement
-Cpanic=abort by killing the process instead of returned a status
code.

Author: c6c7

tests/ui/test-attrs/test-panic-abort-nocapture.rs

@@ -10,6 +10,7 @@
 //@ ignore-wasm no panic or subprocess support
 //@ ignore-emscripten no panic or subprocess support
 //@ ignore-sgx no subprocess support
+//@ ignore-fuchsia code returned as ZX_TASK_RETCODE_EXCEPTION_KILL, FIXME (#58590)
 
 #![cfg(test)]
 

tests/ui/test-attrs/test-panic-abort.rs

@@ -10,6 +10,7 @@
 //@ ignore-wasm no panic or subprocess support
 //@ ignore-emscripten no panic or subprocess support
 //@ ignore-sgx no subprocess support
+//@ ignore-fuchsia code returned as ZX_TASK_RETCODE_EXCEPTION_KILL, FIXME (#58590)
 
 #![cfg(test)]
 #![feature(test)]