rtti3.C: Scan for .weakext on alpha*-dec-osf*.

rtti3.C: Scan for .weakext on alpha*-dec-osf*.

	* g++.dg/abi/rtti3.C: Scan for .weakext on alpha*-dec-osf*.
	* g++.dg/abi/thunk4.C: Likewise.
	* g++.dg/opt/combine.C: Add dg-require-visibility.
	* g++.dg/other/anon5.C: Skip on alpha*-dec-osf*.
	* g++.dg/warn/miss-format-1.C: XFAIL scanf attribute warning on
	alpha*-dec-osf*.
	* g++.dg/warn/pr31246.C: XFAIL on alpha*-dec-osf*.
	* g++.dg/warn/weak1.C: Skip on alpha*-dec-osf*.
	* g++.old-deja/g++.eh/badalloc1.C [!STACK_SIZE && __osf__]: Use
	large arena_size.
	* gcc.dg/attr-weakref-1.c: Skip on alpha*-dec-osf*.
	* gcc.dg/intmax_t-1.c: Likewise.

From-SVN: r166548