pre-table: replaced entry expected with expression return data type

replaced the table expected data type (which was for the old token
centric translator, though also used for operator/function return data
type) with an expression info return data type

modified the preset expression info structure instances with ones that
include the return data type

updated all table entries; note repeat cannot use the preset expression
info because it needs a different return data type than the assign
operators that use the same preset

renamed the data type access function to return data type and modified
it to check if the expression info pointer is not null