[clang] [Clang] Add '-Warray-compare' flag for C++ below version 20 (PR #118031)

[Amr Hesham via cfe-commits]

================
@@ -10264,6 +10264,11 @@ def warn_depr_array_comparison : Warning<
   "to compare array addresses, use unary '+' to decay operands to pointers">,
   InGroup<DeprecatedArrayCompare>;
 
+def warn_array_comparison : Warning<
+  "comparison between two arrays; "
----------------
AmrDeveloper wrote:

I think "comparison between two arrays compare their addresses and will be deprecated in c++20" is good for array-compare and we keep deprecated array compare as it is

https://github.com/llvm/llvm-project/pull/118031