add function compare_members_of_exported_classes to compare
number of members of class definitions in definition and implementation module earlier,
stop checking after checkIclInstances if an error has occurred,
both to prevent compiler crashes for incorrect programs

(modification of bug fix submitted by Mart Lubbers)

this is used if a type synonym is expanded that creates a type application
of an existential variable,
for example :: T a b :== a (T2 b), and a is existential

is created when fusing a case with a constructor pattern containing a variable that
is used more than once

previously the type of the constructor in the type definition was used,
but this is incorrect if the type contains type variables, it introduces (an) unbound variable(s)
(that may cause the compiler to crash) and the type may be too general

(not creating a let appears to be far more common)

when copying an algebraic type extension from the definition to the implementation module

convert member types in module backendconvert,
store pointer from field selector to member type in backend with BESetMemberTypeOfField

prevent compiler crash when importing a generic function definition of a non generic representation type,
for which shorthand instances are generated

for non generic representation types, prevents error when comparing definitions
in implementation and definition module

improve error message in case an instance or generic derived class instances are both defined and imported

try to find a TC dictionary that is used in a dynamic expression also in the dictionaries of constructors
with dictionaries that are used in a pattern match.
First try to find them in convertDynamicTypes in dynamic patterns and function constraints, if that fails,
create an EI_TypeOfDynamicAndTCsToFind, and try again in updateExpression, if that also fails report an error.

optimise the following case: an alternative for each constructor, at least 3, one alternative cannot fail and the other
alternatives yield the same boolean result.
Remove those boolean result alternatives, and add a default with this result.

move calls to expand_type and coerce in module trans to new function expand_and_coerce_type in module unitype

partial function application with one partial function application argument

only fuses (transforms) generic functions and adds an extra
pass before the normal fusion pass that only fuses (transforms)
generic functions, but not recursive producers