[clang] [lld] [llvm] [LTO] Make stack usage files work with LTO (PR #178005)

[Marina Taylor via cfe-commits]

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@@ -106,6 +106,11 @@ static cl::opt<std::string>
     LTOStatsFile("lto-stats-file",
                  cl::desc("Save statistics to the specified file"), cl::Hidden);
 
+cl::opt<std::string>
+    LTOStackUsageOutput("lto-stack-usage-output",
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citymarina wrote:

I'm not sure if I've understood your suggestion correctly, but - I tried marking the cl::opt as extern in llvm-lto2 to  see if it could get picked up from LTOCodeGenerator.cpp (that ought to be in the LLVMLTO library, which llvm-lto2 depends on, right?) but it wasn't visible.

https://github.com/llvm/llvm-project/pull/178005