AIX: Export static library symbols from executables with ENABLE_EXPORTS
Since !3561 (merged) CMake creates an import library for an executable with the
ENABLE_EXPORTS property set. The purpose is to export symbols from the executable such that they can be linked by loadable modules. We do this on Windows too.
However, we are currently only exporting symbols from the object files in the executable target itself. Symbols that are brought into the executable from linked static libraries are not exported on AIX (but they are on Windows if they have