[llvm] [CMake][OCaml] Make OCaml bindings suitable for out-of-tree install (PR #123478)

[John Ericson via llvm-commits]

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@@ -19,8 +19,8 @@ The bindings can also be built out-of-tree, i.e. targeting a preinstalled
 LLVM. To do this, configure the LLVM build tree as follows:
 
     $ cmake -DLLVM_OCAML_OUT_OF_TREE=TRUE \
-            -DCMAKE_INSTALL_PREFIX=[Preinstalled LLVM path] \
-            -DLLVM_OCAML_INSTALL_PATH=[OCaml install prefix] \
+            -DLLVM_OCAML_EXTERNAL_LLVM_LIBDIR=[LLVM libdir, e.g. `llvm-config --libdir`] \
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Ericson2314 wrote:

We shouldn't do this, instead with an `OCAML_BINDINGS_BUILD_STANDALONE` we would do a `findPackage(LLVM ...)`. That in turn would set `LLVM_LIBRARY_DIR` to be the external dir, and we wouldn't need the conditions below.

https://github.com/llvm/llvm-project/pull/123478