check for simulink unsupported property initializations

[BrunoSalami]

What kind of feature is this?

• catch matlab constructs that will fail code generation early on
• specifically, Code generation only supports initial values of class type for constant properties

Your MATLAB/Octave environment

• MATLAB R2017b

MISS_HIT component affected
Choose one or more of the below:

• mh_lint

Describe the solution you'd like
in classes, properties may be initialized in the properties block itself, e.g.

properties
    cats = uint8(6)
end

However, code generation only supports this for assignments that use only build-ins. So custom class constructors / functions won't work, e.g.

properties
   cat = Cat() % Cat being a custom class
end

This is fine when you don't generate code from is but will cause an error during code generation "Code generation only supports initial values of class type for constant properties". It'd be nice if this was caught by miss_hit early on.