Auto merge of #123144 - dpaoliello:arm64eclib, r=GuillaumeGomez,Chris…

…Denton,wesleywiser

Add support for Arm64EC to the Standard Library

Adds the final pieces so that the standard library can be built for arm64ec-pc-windows-msvc (initially added in #119199)

* Bumps `windows-sys` to 0.56.0, which adds support for Arm64EC.
* Correctly set the `isEC` parameter for LLVM's `writeArchive` function.
* Add `#![feature(asm_experimental_arch)]` to library crates where Arm64EC inline assembly is used, as it is currently unstable.