* i386.cc (Target_i386::define_tls_base_symbol): New function.
(Target_i386::tls_base_symbol_defined_): New field.
(Target_i386::Scan::local): Define _TLS_MODULE_BASE_ symbol.
(Target_i386::Scan::global): Likewise.
* symtab.cc (sized_finalize_symbol): Add check for TLS symbol.
* x86_64.cc (Target_x86_64::define_tls_base_symbol): New function.
(Target_x86_64::tls_base_symbol_defined_): New field.
(Target_x86_64::Scan::local): Define _TLS_MODULE_BASE_ symbol.
(Target_x86_64::Scan::global): Likewise.