[compiler-rt] [TSan] Clarify and enforce shadow end alignment (PR #144648)

[Kunqiu Chen via llvm-commits]

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@@ -0,0 +1,32 @@
+// RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
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Camsyn wrote:

I submitted the testcase and fix together in several PRs before, so I did the same this time. 
But your suggestion is really a better practice, and I have put forward a separate PR #145472. :)
After that PR is merged, I will rebase this PR.

https://github.com/llvm/llvm-project/pull/144648