tracking issue - needed PR

[ZuseZ4]

Safety/Frontend side:
Offload call site macro: #8
Offload kernel-side macro: rust-lang/rust#156642

Performance:
Shared memory: rust-lang/rust#154835
+two llvm pr's from Johannes/me

features:
Call cuBlas and other libs (likely broken atm) rust-lang/rust#150683
Explicit data movement (implemented, needs testing): rust-lang/rust#156620

Also, generally building rustc with openmp/offload fails at the moment on main, I have a local workaround, and I think @Sa4dUs is not affected by coincidence.

[ZuseZ4]

main should be fixed in the next llvm submodule update, Tuesday or Wednesday.