8923bac7e8
* Implement emitting Windows unwind information for fastcall functions. This commit implements emitting Windows unwind information for x64 fastcall calling convention functions. The unwind information can be used to construct a Windows function table at runtime for JIT'd code, enabling stack walking and unwinding by the operating system. * Address code review feedback. This commit addresses code review feedback: * Remove unnecessary unsafe code. * Emit the unwind information always as little endian. * Fix comments. A dependency from cranelift-codegen to the byteorder crate was added. The byteorder crate is a no-dependencies crate with a reasonable abstraction for writing binary data for a specific endianness. * Address code review feedback. * Disable default features for the `byteorder` crate. * Add a comment regarding the Windows ABI unwind code numerical values. * Panic if we encounter a Windows function with a prologue greater than 256 bytes in size.