rs6000.c (rs6000_gimple_fold_builtin): Add handling for early folding of vector store...

rs6000.c (rs6000_gimple_fold_builtin): Add handling for early folding of vector stores (ALTIVEC_BUILTIN_ST_*).

[gcc]

2017-09-25  Will Schmidt  <will_schmidt@vnet.ibm.com>

	* config/rs6000/rs6000.c (rs6000_gimple_fold_builtin): Add handling
	for early folding of vector stores (ALTIVEC_BUILTIN_ST_*).
	(rs6000_builtin_valid_without_lhs): New helper function.
	* config/rs6000/rs6000-c.c (altivec_resolve_overloaded_builtin):
	Remove obsoleted code for handling ALTIVEC_BUILTIN_VEC_ST.

From-SVN: r253152