tests: increase coverage for depcomp tests On platforms requiring that no undefined symbols exist in order to build shared libraries (e.g. Windows DLLs), you have to explicitly declare that the libtool library you are building does not actually have any undefined symbols, for libtool to even try to build it as a shared library. Without that explicit declaration, libtool falls back to a static library only, regardless of any --enable-shared flags etc. tests/depcomp.sh (Makefile.am): Add -no-undefined if a libtool library (.la) is built. (src/Makefile.am): Likewise.