The Rust Compiler has recently added support for ARM64EC (https://github.com/rust-lang/rust/pull/119199), so this change adds support for ARM64EC to backtrace by using the same OS structures and functions as x64 NOT AArch64: this is because an ARM64EC binary runs within an x64 process (on an AArch64 machine), thus all the OS binaries it is interfacing with expose the x64 API.
The Rust Compiler has recently added support for ARM64EC (https://github.com/rust-lang/rust/pull/119199), so this change adds support for ARM64EC to backtrace by using the same OS structures and functions as x64 NOT AArch64: this is because an ARM64EC binary runs within an x64 process (on an AArch64 machine), thus all the OS binaries it is interfacing with expose the x64 API.