PR gold/12279

	PR gold/12279
	* resolve.cc (Symbol_table::should_override): Add fromtype
	parameter.  Change all callers.  Give error when linking together
	TLS and non-TLS symbol.
	(Symbol_table::should_override_with_special): Add fromtype
	parameter.  Change all callers.
	* i386.cc (Target_i386::Relocate::relocate_tls): Don't crash if
	there is no TLS segment if we have reported some errors.
	* x86_64.cc (Target_x86_64::relocate_tls): Likewise.