[compiler-rt] [scudo] Add primary option to zero block on dealloc. (PR #142394)

[via llvm-commits]

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@@ -34,6 +34,10 @@ SCUDO_FLAG(bool, delete_size_mismatch, true,
 
 SCUDO_FLAG(bool, zero_contents, false, "Zero chunk contents on allocation.")
 
+SCUDO_FLAG(bool, zero_on_dealloc, false,
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piwicode wrote:

Yes. I took the time to confirm that we need this to disable the feature on devices where the cpu/memory tradeoff is different. This will be used on day 1.
I turned the flag into a limit according to previous suggestion, and added a compiletime parameter `EnableZeroOnDealloc` so that the code can be stripped out by the compiler.

https://github.com/llvm/llvm-project/pull/142394