…ories.

We better make this configurable. Because sometimes we want to compile only the files
in the immediate directory.

Use ref and appliedTo instead.

The idea to traverse with currently enclosing methid is also used in
LambdaLift and could be used elsewhere.

…lled.

Instead of requiring to be called a given phase, change the context if
that is not the case.

Lifting an application  `f(arg1).f(args)` requires lifting of the whole prefix
`f(arg1)`, because `f` might have a side effect.

Advantage: Can rename typed as well as untyped trees.

Previously, we determined the default getters solely from the method TermRef type.
This is wrong if the method is prefix is not a path -- the prefix of the term ref will be a
TypeRef and the getter selection will be a SelectFromType tree, which makes no sense.

It changes meaning drastically so should always be visible.

Some transformations encounter applications where new arguments ahve to be
supplied. The method type already accounts for these argument but the
Application node passed into TreeTransform#transformApply is constructed
with a cpy.Apply operation which does a type assignment. That type assignment
fails with a parameter mismatch unless relaxedTyping is on.

Environment parameters do not count in th eresult type.

The current formulation of lambda lift is easier to do if that's the case.

Need to drop all non-class type declarations.

Params are already added by Desugar. No special treatment needed here.
Besides primaryConstructor.typeParams is always empty, because term symbols
do not have type parameters.

The fix turns t2660.scala into an error. I believe the error is correct, hence
the test was moved with a comment to neg.

Primary constructor was picking last constructor instead of first one.
This is now fixed. Also, added paramAccessors utility method.

Needed to fix a problem in CapturedVars to make this work.

Like the corresponding parameters, these also need to be rewritten to function types.

1) Type parameters are now copied to accessors
2) Constructors also work for traits

2) makes it possible do to mixin after constructors.

TypeVars can appear as keys in baseType caches. The problem is that
their base types depend on their instantiation, which is not always
know yet when the test is performed. So results of baseType on
type variables should never be cached.

Todo: check whether there are any other caching problems involving typevars.

Typevars can be parts of larger types or underlying types of
other types, which renders these other types uncacheable. The new
logic takes account of that.

Private fields that are accessed only from the constructor,
and are accessed only after they are properly initialized are now
moved into the constructor. This avoids creating a redundant objetc field.
Good example: gcd in Rationals (see constrs.scala).

TypeVar is a TypeProxy.

Allow to skip labels.

A cast like

    expr.asInstanceOf[x.type]

where x is a by-name parameter has to be mapped to

    expr.asInstanceOf[x.type].apply()

See pos/t296.scala which would otherwise start failing when the pattern matcher is integrated.

…ansform/constructors

Conflicts:
	src/dotty/tools/dotc/transform/ElimByName.scala