hooks for naming and synthesis in Namers.scala and Typers.scala

Interestingly enough, despite of the implementation surface being
quite noticeable, it is enough to hijack just `enterSym` and typechecking
of stats for packages, templates and blocks in order to enable macro annotations.
That and `ensureCompanionObject`, which I couldn't abstract away so far.

An architectural note: given that a hooked method is called `X`,
there are two implementations of this method. `pluginsX` is defined in
AnalyzerPlugins.scala and lets macro plugins customize `X`.
`standardX` is defined next to `X` and provides a default implementation.
Finally `X` is changed to trivially forward to `pluginsX`.

Existing and future callers of `X` now can be completely oblivious of the
introduced hooks, because calls to `X` will continue working and will be
correctly hooked. This makes the infrastructure more robust.

The only downside is that in case when a macro plugin wants to call
into the default implementation, it needs to call `standardX`, because
`X` will lead to a stack overflow. However, in my opinion this not a big
problem, because such failures are load and clear + for every `pluginsX`
we actually provide documentation that says what is its standard impl is.

1 files changed, 1 insertions, 1 deletions

diff --git a/test/files/run/macroPlugins-typedMacroBody/Plugin_1.scala b/test/files/run/macroPlugins-typedMacroBody/Plugin_1.scala
index 4632c36ef5..e99cf7f75d 100644
--- a/test/files/run/macroPlugins-typedMacroBody/Plugin_1.scala
+++ b/test/files/run/macroPlugins-typedMacroBody/Plugin_1.scala
@@ -15,7 +15,7 @@ class Plugin(val global: Global) extends NscPlugin {
   object MacroPlugin extends MacroPlugin {
     override def pluginsTypedMacroBody(typer: Typer, ddef: DefDef): Option[Tree] = {
       val DefDef(_, _, _, _, _, Literal(Constant(num: Int))) = ddef
-      Some(typedMacroBody(typer, copyDefDef(ddef)(rhs = Ident(TermName("impl" + num)))))
+      Some(standardTypedMacroBody(typer, copyDefDef(ddef)(rhs = Ident(TermName("impl" + num)))))
     }
   }
 }
\ No newline at end of file