Teach Visual Studio generators to include object files from object
libraries in the list of objects whose symbols are to be exported.
The Makefile and Ninja generators already did this. Update the
test to cover this case.
Reported-by: Bertrand Bellenot <Bertrand.Bellenot@cern.ch>
Create target property WINDOWS_EXPORT_ALL_SYMBOLS to automatically
generate a module definition file from MS-compatible .obj files and give
it to the linker in order to export all symbols from the .dll part of a
SHARED library.