libitm port to Tru64 UNIX

libitm port to Tru64 UNIX

	* config/alpha/sjlj.S (_ITM_beginTransaction) [!__ELF__]: Don't use
	.hidden.
	(.note.GNU-stack): Only use if __linux__.
	* alloc_cpp.cc [!__osf__] (_ZnaXRKSt9nothrow_t): Dummy function.
	* testsuite/libitm.c/notx.c: Use dg-options "-pthread".
	* testsuite/libitm.c/reentrant.c: Likewise.
	* testsuite/libitm.c/simple-2.c: Likewise.
	* testsuite/libitm.c/txrelease.c: Likewise.
	* testsuite/libitm.c++/static_ctor.C: Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@181262 138bc75d-0d04-0410-961f-82ee72b054a4