Ignore crash test that doesn't crash on Apple platforms

This wasn't caught by CI, because debug assertions aren't enabled there.

Author: madsmtm

tests/crashes/120175.rs

@@ -1,5 +1,6 @@
 //@ known-bug: #120175
 //@ needs-rustc-debug-assertions
+//@ ignore-apple (raw-dylib doesn't work on Apple targets yet)
 
 #![feature(extern_types)]
 #![feature(raw_dylib_elf)]