On macOS, valid syscall numbers all have a high bit set, leaving the low range "invalid" to be caught by SIGSYS.
On a Mac running macOS 14 or later, the test passes.
macOS 13 and earlier have a kernel bug which prevents SIGSYS from being delivered.
This patch was adapted from Apple's Game Porting Toolkit Wine patch, and from the 'ntdll-Syscall_Emulation' wine-staging patchset.
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https://gitlab.winehq.org/wine/wine/-/merge_requests/6777
Some FOURCC values such as 0xdeadbeef will en up being negative when cast to the
enum type, and may cause a random crash later on. This happens randomly in the
ddraw tests, depending on the compiler being used.
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https://gitlab.winehq.org/wine/wine/-/merge_requests/6698