[llvm] [Sanitizer] Make sanitizer passes idempotent (PR #99439)

[Vitaly Buka via llvm-commits]

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@@ -0,0 +1,56 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals all --version 5
+; This test checks in the second run, function is not instrumented again.
+; RUN: opt < %s -passes=asan,asan -S | FileCheck %s
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vitalybuka wrote:

@nikic We don't have such instrumenting sanitizers yet, but having unique flags is LGTM

@efriedma-quic all previous proposals to add such "re-run" protection ended up with "the pipeline is wrong". But implementation is so trivial, so I don't mind just to have it implemented.

https://github.com/llvm/llvm-project/pull/99439