PR target/63901
	* configure.host (msp430): Add -mhwmult=none to newlib_cflags.
	* init.cc (dll_entry): Revert previous patch.  This requires another
	solution.
	* miscfuncs.cc (thread_wrapper): Ditto.
	* sigproc.cc (exit_thread): Disable sending a signal for synchronization
	with process exit.  Explain why.  Keep code in for later inspection,
	should the problem show up again.
	(sig_send): Use "tls", rather than "tid" as name for _cygtls arg.
	* init.cc (dll_entry): Revert previous patch.  This requires another
	solution.
	* miscfuncs.cc (thread_wrapper): Ditto.
	* sigproc.cc (exit_thread): Disable sending a signal for synchronization
	with process exit.  Explain why.  Keep code in for later inspection,
	should the problem show up again.
	(sig_send): Use "tls", rather than "tid" as name for _cygtls arg.