`asm!` and `global_asm!` moved to `core::arch`

[mattlgy]

rust-lang/stdarch#1183 moved the asm macros the core::arch namespace. Currently, things don't compile with a recent nightly. Using a nightly from before the move works as a workaround.

[mattlgy]

This seems like a pretty easy fix. Planning to add the using statements to the relevant files today/tomorrow, but figured I would open an issue first.

[Lokathor]

Ah yeah, i saw the stabilization report but forgot that the macro moved.