[llvm] [BOLT] Enable standalone build (PR #97130)

[Konrad Kleine via llvm-commits]

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@@ -9,6 +20,42 @@ set(CMAKE_CXX_STANDARD 17)
 # Add path for custom modules.
 list(INSERT CMAKE_MODULE_PATH 0 "${BOLT_SOURCE_DIR}/cmake/modules")
 
+include(GNUInstallDirs)
+
+# standalone build, copied from clang
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kwk wrote:

I doubt that this is a 1:1 copy from Clang. See comment below.

https://github.com/llvm/llvm-project/pull/97130