Mux0X cond type change: verify all isel cases, and implement one
that got missed (for F64).


git-svn-id: svn://svn.valgrind.org/vex/trunk@2666 8f6e269a-dfd6-0310-a8e1-e2731360e62c
Mux0X cond type change: fix a front end case that got missed.


git-svn-id: svn://svn.valgrind.org/vex/trunk@2667 8f6e269a-dfd6-0310-a8e1-e2731360e62c