* late instantiation for the generic procs' default param values
* automatic mixin behaviour in concepts
Other fixes:
* don't render the automatically inserted default params in calls
* better rendering of tyFromExpr
* fix the usage of unresolved static[T] parameters in proc signatures
* fix tsametype and tmacrogenerics
* Allow creating composite type classes with concepts and using them in type signatures
* Allow integers to be used in ident concatenations
* Support using imported C++ generic types in proc signatures
* fixes#7230
* closes#7379
* re-enable some metatype tests
During the instantiation of a generic type A, some other generic
type B may be instantiated multiple times with different parameters.
We can think about each instantiation as a function call that should
temporary bind the parameter names to concrete types. The problem
with the existing implementation in semtypinst was that it was
performing this binding within a shared global table. In this sense,
it was executing the code as a programming language featuring only
global variables. In such a language, re-entrant functions cannot be
defined properly and hence this was leading to problems with similar
types. The solution is simple - just like we need to introduce stack
frames to handle re-entrant functions, we introduce a stack of type
bindings that are pushed and popped during the generic instantiations.
A more efficient implementation is possible by restoring the old
lifting ot tyGenericInvocation to tyGenericInst in liftTypeParam,
but this fix will suffice for now.
fixes#5087fixes#5602fixes#5641fixes#5570
