re PR libgcj/49315 (Throw_2 SEGVs on Tru64 UNIX)

re PR libgcj/49315 (Throw_2 SEGVs on Tru64 UNIX)

	PR libgcj/49315
	* include/solaris-signal.h: Rename to ...
	* include/posix-signal.h: ... this.
	(SA_FLAGS): Define.
	(SIGNAL_HANDLER): Handle non-SA_SIGINFO case.
	(sa_signal_handler): Define.
	(_INIT_SIG_HANDLER): New macro.
	(INIT_SEGV, INIT_FPE): Use it.
	* configure.ac (SIGNAL_HANDLER): Use it on alpha*-dec-osf*,
	mips-sgi-irix*, *-*-solaris2*
	* configure: Regenerate.
	* include/aix-signal.h: Refer to AIX.
	* configure.host (alpha*-dec-osf*): Enable can_unwind_signal.
	(mips-sgi-irix6*): Likewise.

From-SVN: r175138