[PATCH] [PowerPC] Initial VSX intrinsic support, with min/max for vector double

[hfinkel at anl.gov]

LGTM.

================
Comment at: test/CodeGen/PowerPC/vsx-minmax.ll:77
@@ +76,3 @@
+
+attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone }
----------------
Remove unnecessary attributes.

================
Comment at: test/CodeGen/PowerPC/vsx-minmax.ll:83
@@ +82,3 @@
+
+!0 = metadata !{metadata !"clang version 3.6.0 (trunk 220384) (llvm/trunk 220384:220395M)"}
+!1 = metadata !{metadata !2, metadata !2, i64 0}
----------------
Remove unnecessary metadata.

http://reviews.llvm.org/D5948