[clang] [sanitizer] Add plumbing for -fsanitize-add-pseudo-functions and partly replace '-mllvm -array-bounds-pseudofn' (PR #138577)

[Thurston Dang via cfe-commits]

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@@ -2533,6 +2533,31 @@ def fno_sanitize_merge_handlers : Flag<["-"], "fno-sanitize-merge">, Group<f_cla
                         Alias<fno_sanitize_merge_handlers_EQ>, AliasArgs<["all"]>,
                         Visibility<[ClangOption, CLOption]>,
                         HelpText<"Do not allow compiler to merge handlers for any sanitizers">;
+def fsanitize_add_pseudo_functions_EQ
+    : CommaJoined<["-"], "fsanitize-add-pseudo-functions=">,
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thurstond wrote:

`-fsanitize-pseudo-function` is slightly ambiguous: it sounds like it is an option to sanitize any existing pseudo-functions, rather than sanitizers adding pseudo-functions

https://github.com/llvm/llvm-project/pull/138577