re PR target/34526 (no-altivec ABI should be fixed or no longer be the default)

re PR target/34526 (no-altivec ABI should be fixed or no longer be the default)

	PR target/34526
	* config/rs6000/rs6000.c (rs6000_altivec_abi): Clarify comment.
	(rs6000_explicit_options): Split abi into spe_abi and altivec_abi,
	add vrsave.
	(rs6000_override_options): Set altivec_abi as default, not override,
	for 64-bit GNU/Linux; for 32-bit GNU/Linux default to altivec_abi for
	TARGET_ALTIVEC; default to TARGET_ALTIVEC_VRSAVE when AltiVec ABI
	is used; use new member spe_abi.
	(rs6000_handle_option): Set rs6000_explicit_options.vrsave; use
	spe_abi and altivec_abi.

From-SVN: r132537