refine block and applied/typeapplied splicing/matching semantics

1. blocks now match single term-level expressions to account for
   automatic block elimination. E.g.

   val q"{ ..$stats }" = q"foo"

   will match into stats = List(q"foo"). This is useful to uniformly
   deal with blocks on term level.

2. blocks in quasiquotes collapse into single expressions

3. Applied and TypeApplied now have constructors too which helps
   to unify matching and extraction in quasiquote reifier

4. TypeApplied now matches AppliedTypeTree too

5. Add Syntactic prefix to Applied and TypeApplied

1 files changed, 5 insertions, 3 deletions

diff --git a/test/files/scalacheck/quasiquotes/TermConstructionProps.scala b/test/files/scalacheck/quasiquotes/TermConstructionProps.scala
index 5a765f7911..599dfd442a 100644
--- a/test/files/scalacheck/quasiquotes/TermConstructionProps.scala
+++ b/test/files/scalacheck/quasiquotes/TermConstructionProps.scala
@@ -88,7 +88,7 @@ object TermConstructionProps extends QuasiquoteProperties("term construction") {
   }
 
   property("splice trees into type apply") = forAll { (fun: TreeIsTerm, types: List[Tree]) =>
-    q"$fun[..$types]" ≈ TypeApply(fun, types)
+    q"$fun[..$types]" ≈ (if (types.nonEmpty) TypeApply(fun, types) else fun)
   }
 
   property("splice names into import selector") = forAll {
@@ -122,8 +122,10 @@ object TermConstructionProps extends QuasiquoteProperties("term construction") {
 
   def blockInvariant(quote: Tree, trees: List[Tree]) =
     quote ≈ (trees match {
-      case Nil => Block(Nil, q"()")
-      case _   => Block(trees.init, trees.last)
+      case Nil => q"()"
+      case _ :+ last if !last.isTerm => Block(trees, q"()")
+      case head :: Nil => head
+      case init :+ last => Block(init, last)
     })
 
   property("splice list of trees into block (1)") = forAll { (trees: List[Tree]) =>