[Migrated] debug_printf requires unsafe

Issue automatically imported from old repo: https://github.com/EmbarkStudios/rust-gpu/issues/997
Old labels: t: enhancement
Originally creatd by charles-r-earp on 2023-03-04T00:38:43Z

The debug_printf and debug_printfln macros generate an invocation of the asm macro, which requires an unsafe block. However, the macro appears to validate it's input, so it could potentially add the unsafe block to it's output. If there are still outstanding issues, perhaps a safety section could be added to the docs to reduce confusion? This is a really useful tool, and it seems strange to require unsafe just to debug stuff.

Iniziate dalle definizioni delle macro debug_printf e debug_printfln e dalla macro asm che invocano. Verificate in che modo la convalida dell’input è correlata al requisito unsafe, quindi stabilite se il completamento consiste nel modificare l’invocazione generata o nel documentare le aspettative di sicurezza.