* dynobj.cc (Versions::Versions): Initialize version_script_.
Only insert base version symbol definition for a shared object
if version script defines any version versions.
(Versions::define_base_version): New method definition.
(Versions::add_def): Check that base version is not needed.
(Versions::add_need): Define base version lazily.
* dynobj.h (Versions::define_base_version): New method declaration.
(Versions::needs_base_version_): New data member declaration.
* testsuite/Makefile.am (check_SCRIPTS): Add no_version_test.sh
(check_DATA): Add no_version_test.stdout.
(libno_version_test.so, no_version_test.o no_version_test.stdout):
New make rules.
* testsuite/Makefile.in: Regenerate.
* testsuite/no_version_test.c: New file.
* testsuite/no_version_test.sh: Ditto.
