[clang] [Clang] Initialize bypassed variables w/ trivial-auto-var-init (PR #181937)

[Justin Stitt via cfe-commits]

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@@ -1544,8 +1544,12 @@ void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn,
       ShouldEmitLifetimeMarkers = true;
 
     // Initialize helper which will detect jumps which can cause invalid
-    // lifetime markers.
-    if (ShouldEmitLifetimeMarkers)
+    // lifetime markers or bypass trivial auto var init.
+    bool NeedsBypassDetection =
+        ShouldEmitLifetimeMarkers ||
+        (CGM.getLangOpts().getTrivialAutoVarInit() !=
+         LangOptions::TrivialAutoVarInitKind::Uninitialized);
+    if (NeedsBypassDetection)
       Bypasses.Init(CGM, Body);
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JustinStitt wrote:

@efriedma-quic 
PTAL:

>From `Commit 29391328ab66 ("[WebAssembly][GlobalISel] CallLowering lowerFormalArguments (#180263)")` to my commit [`c5cb892` (this PR)](https://github.com/llvm/llvm-project/pull/181937/commits/c5cb892acb55f149e35e88b42b415368e250bd11) we get [these results](https://llvm-compile-time-tracker.com/compare.php?from=29391328ab66052b03babb2d147615f180827793&to=c5cb892acb55f149e35e88b42b415368e250bd11&stat=instructions:u).

... which when looking at `-O0` builds we see results that look to be within noise levels? (I am not an expert at using this tool).



https://github.com/llvm/llvm-project/pull/181937