Annotate ARMNImm_to_Imm64 with fallthrough markers following
verification against the table in host_arm_defs.h, "Neon Immediate
operand".  A particularly nasty piece of code.



git-svn-id: svn://svn.valgrind.org/vex/trunk@2661 8f6e269a-dfd6-0310-a8e1-e2731360e62c