Get rid of Thicket(List(...)) as an expression

Thicket has a vararg constructor, so this syntax is redundant.

Author: odersky

src/dotty/tools/dotc/parsing/Parsers.scala

@@ -614,7 +614,7 @@ object Parsers {
       val interpolator = in.name
       in.nextToken()
       while (in.token == STRINGPART) {
-        segmentBuf += Thicket(List(
+        segmentBuf += Thicket(
             literal(),
             atPos(in.offset) {
               if (in.token == IDENTIFIER)
@@ -630,7 +630,7 @@ object Parsers {
                 syntaxErrorOrIncomplete("error in interpolated string: identifier or block expected")
                 EmptyTree
               }
-            }))
+            })
       }
       if (in.token == STRINGLIT) segmentBuf += literal()
       InterpolatedString(interpolator, segmentBuf.toList)

src/dotty/tools/dotc/transform/LazyVals.scala

@@ -220,14 +220,14 @@ class LazyVals extends MiniPhaseTransform with IdentityDenotTransformer {
         val containerTree = ValDef(containerSymbol, defaultValue(tpe))
         if (x.tpe.isNotNull && tpe <:< defn.ObjectType) { // can use 'null' value instead of flag
           val slowPath = DefDef(x.symbol.asTerm, mkDefNonThreadSafeNonNullable(containerSymbol, x.rhs))
-          Thicket(List(containerTree, slowPath))
+          Thicket(containerTree, slowPath)
         }
         else {
           val flagName = ctx.freshName(x.name ++ StdNames.nme.BITMAP_PREFIX).toTermName
           val flagSymbol = ctx.newSymbol(x.symbol.owner, flagName,  containerFlags | Flags.Private, defn.BooleanType).enteredAfter(this)
           val flag = ValDef(flagSymbol, Literal(Constants.Constant(false)))
           val slowPath = DefDef(x.symbol.asTerm, mkNonThreadSafeDef(ref(containerSymbol), ref(flagSymbol), x.rhs))
-          Thicket(List(containerTree, flag, slowPath))
+          Thicket(containerTree, flag, slowPath)
         }
     }
 
@@ -390,8 +390,8 @@ class LazyVals extends MiniPhaseTransform with IdentityDenotTransformer {
 
         val accessor = mkThreadSafeDef(x.symbol.asTerm, claz, ord, containerSymbol, x.rhs, tpe, offset, getFlag, state, cas, setFlag, wait)
         if (flag eq EmptyTree)
-          Thicket(List(containerTree, accessor))
-        else Thicket(List(containerTree, flag, accessor))
+          Thicket(containerTree, accessor)
+        else Thicket(containerTree, flag, accessor)
     }
 }