[lld] [llvm] [lld] Add caching for `--lto-partitions` (PR #212203)

[Konstantin Belochapka via llvm-commits]

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@@ -660,6 +660,11 @@ def lto_CGO: JJ<"lto-CGO">, MetaVarName<"<cgopt-level>">,
   HelpText<"Codegen optimization level for LTO">;
 def lto_partitions: JJ<"lto-partitions=">,
   HelpText<"Number of LTO codegen partitions">;
+def lto_partitions_cache_dir: JJ<"lto-partitions-cache-dir=">,
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kbelochapka wrote:

Hi @Pierre-vh , reusing the ThinLTO cache would shorten this path while keeping all the intended functionality.

https://github.com/llvm/llvm-project/pull/212203