Move ElimRepeated miniphase to an earlier group

ByNameLambda needs to run in a group after ElimRepeated since ElimRepeated
works on ByName arguments but not converted closures, and it sees the arguments
after transformations by subsequent miniphases in the same group.

Author: odersky

compiler/src/dotty/tools/dotc/Compiler.scala

@@ -67,10 +67,10 @@ class Compiler {
          new CheckLoopingImplicits,  // Check that implicit defs do not call themselves in an infinite loop
          new BetaReduce,             // Reduce closure applications
          new InlineVals,             // Check right hand-sides of an `inline val`s
-         new ExpandSAMs) ::          // Expand single abstract method closures to anonymous classes
+         new ExpandSAMs,             // Expand single abstract method closures to anonymous classes
+         new ElimRepeated) ::        // Rewrite vararg parameters and arguments
     List(new init.Checker) ::        // Check initialization of objects
-    List(new ElimRepeated,           // Rewrite vararg parameters and arguments
-         new ByNameLambda,           // Replace by-name applications with closures
+    List(new ByNameLambda,           // Replace by-name applications with closures
          new ProtectedAccessors,     // Add accessors for protected members
          new ExtensionMethods,       // Expand methods of value classes with extension methods
          new UncacheGivenAliases,    // Avoid caching RHS of simple parameterless given aliases

compiler/src/dotty/tools/dotc/transform/ByNameLambda.scala

@@ -18,6 +18,11 @@ class ByNameLambda extends MiniPhase, IdentityDenotTransformer:
 
   def phaseName: String = ByNameLambda.name
 
+  override def runsAfterGroupsOf: Set[String] = Set(ElimRepeated.name)
+    // ByNameLambda needs to run in a group after ElimRepeated since ElimRepeated
+    // works on ByName arguments but not converted closures, and it sees the arguments
+    // after transformations by subsequent miniphases in the same group.
+
   override def transformApply(app: Apply)(using Context): Tree = app match
     case ByName(body) =>
       body match