[llvm] [CMake] Make ELF library handling path default for libLLVM (PR #74698)

[Fangrui Song via llvm-commits]

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@@ -60,8 +53,6 @@ if(LLVM_BUILD_LLVM_DYLIB)
       # inside and outside libLLVM.so.
       target_link_options(LLVM PRIVATE LINKER:-Bsymbolic-functions)
     endif()
-  elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin")
-    set(LIB_NAMES -Wl,-all_load ${LIB_NAMES})
   endif()
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MaskRay wrote:

I think we can generalize `message(FATAL_ERROR "Generating libLLVM is not supported on z/OS")` to all non-ELF-non-MachO OSes and place the fatal error in the `else` branch.

https://github.com/llvm/llvm-project/pull/74698