rotate CallInst operands

with this commit the callee moves to the end of
the operand array (from the start) and the call
arguments now start at index 0 (formerly 1)

this ordering is now consistent with InvokeInst

this commit only flips the switch,
functionally it is equivalent to
r101465

I intend to commit several cleanups after a few
days of soak period

llvm-svn: 108240