[clang] [lld] [llvm] Integrated Distributed ThinLTO (DTLTO): Initial support (PR #126654)

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@@ -969,6 +969,10 @@ def Xlinker : Separate<["-"], "Xlinker">, Flags<[LinkerInput, RenderAsInput]>,
   Visibility<[ClangOption, CLOption, FlangOption]>,
   HelpText<"Pass <arg> to the linker">, MetaVarName<"<arg>">,
   Group<Link_Group>;
+def Xdist : Separate<["-"], "Xdist">, Flags<[LinkOption]>,
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bd1976bris wrote:

Good comment, thanks. In this implementation, there are two things to which a user might want to pass arguments:

1. A distributor – which is whatever process is invoked to consume the JSON and distribute the ThinLTO backend compilations.
2. Whatever tool will be invoked by the distributors to perform the ThinLTO backend compilations – in this PR, that is currently `clang`; however, we refer to this as the `remote optimization tool` since it is possible to swap to a different tool without changing the distributors.

We went with `-Xdist` as it indicates that the arguments will be forwarded to the distributor process and is short (to reduce verbosity if there are many forwarded arguments). What would you think about `-Xthinlto-distributor=` instead?

https://github.com/llvm/llvm-project/pull/126654