Implement a `trap()` function
The trap() function issues an illegal instruction on supported architectures, falling back to calling abort() elsewhere. It is semantically equivalent to the llvm.trap and __builtin_abort() intrinsics.
On some architectures, issuing an illegal instruction is cheaper than calling an abort function.
The trap function can be used to implement the abort() function by enabling the trap-via-abort feature. This feature does nothing if the architecture is unsupported.
Currently supported architectures for trap:
- x86_64
- i686 (x86)
- aarch64
- arm
- wasm32
- wasm64
On nightly, the trap function wraps the core::intrisnics::abort() function.
Additional fixes:
- Use
doc(cfg(...))to document feature requirements - Properly configure feature flags for docs.rs
- Drop
rustversiondependency in favor of detection inbuild.rsscript.