Description

Changes the type of sighandler_t on windows from usize to *const c_void as per #1637 to more accurately represent the fact that it is a pointer to a function (since the value of the address is also sometimes matched without dereferencing it).

A better type would be Option<extern fn ...> however because of the dual use of sighandler_t as a constant, it would be undefined behavior to construct that type from something like 5.

Sources

https://github.com/msys2/msys2-runtime/blob/23a25d49e3b8c18f12ce588869d4cb24de9f2454/newlib/libc/machine/cris/sys/signal.h#L23

Checklist

• Relevant tests in libc-test/semver have been updated
• No placeholder or unstable values like *LAST or *MAX are
  included (see #3131)
• Tested locally (cd libc-test && cargo test --target mytarget);
  especially relevant for platforms that may not be checked in CI