[clang] [llvm] [analyzer] Delete `alpha.security.MallocOverflow` (PR #103059)

[Donát Nagy via cfe-commits]

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@@ -1039,10 +1039,6 @@ def ArrayBoundCheckerV2 : Checker<"ArrayBoundV2">,
   HelpText<"Warn about buffer overflows (newer checker)">,
   Documentation<HasDocumentation>;
 
-def MallocOverflowSecurityChecker : Checker<"MallocOverflow">,
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NagyDonat wrote:

Now that I think about it, we already have lots of precedent for moving and renaming alpha checkers without prior warning, so the "updated to the new version and the old command line invocation doesn't work without changes" situation is not a problem.

The only difference is that after this change they won't be able to restore the behavior by using a new name for the checker, but I think that this is acceptable, because:
1. this checker is so unreliable that it's extremely unlikely that somebody was relying on it;
2. deleting a checker is a _conservative_ change: it removes the results of that particular checker, but it doesn't affects the results of the other checkers and doesn't hinder the investigation of the results by introducing lots of spammy results.

Based on this, I'm merging this commit now.

https://github.com/llvm/llvm-project/pull/103059