* symtab.cc (Symbol_table::add_from_relobj): When not exporting
symbols from this object, don't change the visibility of an
undefined symbol.
* testsuite/exclude_libs_test_1.c (lib1_ref): New function.
* archive.cc (Archive::Archive): Move constructor from archive.h
to here. Initialize no_export_.
(Archive::get_elf_object_for_member): Set no_export flag of object.
* archive.h (Archive::Archive): Move constructor body to
archive.cc.
(Archive::no_export): New method.
(Archive::no_export_): New field.
* object.h (Object::Object): Initialize no_export_ to false.
(Object::no_export, Object::set_no_export): New methods.
(Object::no_export_): New field.
* options.cc (General_options::parse_exclude_libs): New method.
(General_options::check_excluded_libs) Same.
* options.h (exclude_libs): New option.
(General_options::check_excluded_libs): New method declaration.
(General_options::excluded_libs_): New field.
* symtab.cc (Symbol_table::add_from_relobj): Hide symbols with
default or protected visibility if an object has no-export flag set.
testsuite/Makefile.am (check_PROGRAMS): Add exclude_libs_test.
(check_SCRIPTS): Add exclude_libs_test.sh.
(check_DATA): Add exclude_libs_test.syms.
(MOSTLYCLEANFILES): Add exclude_libs_test.syms,
libexclude_libs_test_1.a and libexclude_libs_test_2.a.
(exclude_libs_test_SOURCES, exclude_libs_test_DEPENDENCIES,
exclude_libs_test_LDFLAGS and exclude_libs_test_LDADD): Define.
(exclude_libs_test.syms, libexclude_libs_test_1.a,
libexclude_libs_test_2.a): New rules.
* testsuite/Makefile.in: Regenerate.
* testsuite/exclude_libs_test.c: New file.
* testsuite/exclude_libs_test.sh: Ditto.
* testsuite/exclude_libs_test_1.c: Ditto.
* testsuite/exclude_libs_test_2.c: Ditto.
