[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.

debug_printf と debug_printfln のマクロ定義、およびそれらが呼び出す asm マクロから始めてください。入力検証が unsafe 要件とどのように関係するかを確認し、そのうえで、完了に必要なのが生成される呼び出しの変更なのか、安全性に関する想定の文書化なのかを判断してください。