[clang] [Driver][BoundsSafety] Add -fbounds-safety-experimental flag (PR #70480)

[Fangrui Song via cfe-commits]

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@@ -330,6 +330,14 @@ def warn_alias_with_section : Warning<
   "as the %select{aliasee|resolver}2">,
   InGroup<IgnoredAttributes>;
 
+let CategoryName = "Bounds Safety Issue" in {
+def err_bounds_safety_lang_not_supported : Error<
+  "bounds safety is only supported for C">;
+def warn_bounds_safety_asm_ignored : Warning<
+  "'-fbounds-safety' is ignored for assembly">,
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MaskRay wrote:

https://maskray.me/blog/2023-08-25-clang-wunused-command-line-argument has some notes. If you don't call functions like `getLastArg` that `claim` the option, there will be a `warning: argument unused during compilation: '-fsanitize=address' [-Wunused-command-line-argument]` for assembly input.

https://github.com/llvm/llvm-project/pull/70480