Split assign into two functions
Split assign into two functions

incdec() is an special case of an assigment, so it is a good idea
to merge these two functions in only one. But the semantic actions
of assign were done in assign(), so it was not possible share them
with another rule.

k0gaMSX/scc,k0gaMSX/kcc,8l/scc,8l/scc,k0gaMSX/scc,k0gaMSX/scc,8l/scc,k0gaMSX/kcc