move sequence instance to individual SIMD types rather than simd-128 parent type so that "hashcode*" doesn't attempt to use the sequence implementation of hashcode on abstract simd-128 objects

basis/math/vectors/simd/simd.factor

@@ -230,6 +230,8 @@ BOA-EFFECT define-inline
 M: A pprint-delims drop \ A{ \ } ;
 SYNTAX: A{ \ } [ >A ] parse-literal ;
 
+INSTANCE: A sequence
+
 c:<c-type>
     byte-array >>class
     A >>boxed-class
@@ -249,8 +251,6 @@ PRIVATE>
 
 >>
 
-INSTANCE: simd-128 sequence
-
 ! SIMD instances
 
 SIMD-128: char-16