[clang] [AIX] Fix AIX BuildBot failure as AIX linker doesn't support version script. (PR #117342)

[Aaron Puchert via cfe-commits]

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@@ -48,11 +48,13 @@ add_clang_library(clang-cpp
                   ${_OBJECTS}
                   LINK_LIBS
                   ${_DEPS})
+# AIX linker does not support version script
+if (NOT ${CMAKE_SYSTEM_NAME} MATCHES "AIX")
+  configure_file(simple_version_script.map.in simple_version_script.map)
 
-configure_file(simple_version_script.map.in simple_version_script.map)
-
-if (CMAKE_SYSTEM_NAME STREQUAL "Linux")
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aaronpuchert wrote:

This implies `NOT ${CMAKE_SYSTEM_NAME} MATCHES "AIX"`, hence the `target_link_options` is already unreachable.

https://github.com/llvm/llvm-project/pull/117342