[clang] [flang] [flang] Enable alias tags pass by default (PR #73111)

[Slava Zakharin via cfe-commits]

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@@ -142,6 +142,26 @@ void Flang::addCodegenOptions(const ArgList &Args,
   if (shouldLoopVersion(Args))
     CmdArgs.push_back("-fversion-loops-for-stride");
 
+  Arg *aliasAnalysis = Args.getLastArg(options::OPT_falias_analysis,
+                                       options::OPT_fno_alias_analysis);
+  Arg *optLevel =
+      Args.getLastArg(options::OPT_Ofast, options::OPT_O, options::OPT_O4);
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vzakhari wrote:

It looks like `clang` generates `tbaa` metadata at all opt levels, except `-O0`.  I think this makes sense: the optimization themselves need to decide how to use it, e.g. for improving performance/code-size/etc.

https://github.com/llvm/llvm-project/pull/73111