[clang] [clang][SafeBuffers] Add -Wunsafe-buffer-usage-main-argv to allow ignoring main() argument warnings (PR #229871)

[via cfe-commits]

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@@ -13914,10 +13914,21 @@ def err_cast_from_randomized_struct : Error<
   "casting from randomized structure pointer type %0 to %1">;
 
 // Unsafe buffer usage diagnostics.
+def warn_unsafe_buffer_variable_main_argv : Warning<
+  "%0 is an %select{unsafe pointer used for buffer access|unsafe buffer that "
+  "does not perform bounds checks}1">,
+  InGroup<UnsafeBufferUsageMainArgv>, DefaultIgnore;
+
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shreya-jain wrote:

Done here and below

https://github.com/llvm/llvm-project/pull/229871