Patch x: _* into x* (not x *)

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

@@ -2344,7 +2344,7 @@ object Parsers {
               in.sourcePos(uscoreStart),
               future)
             if sourceVersion == `future-migration` then
-              patch(source, Span(t.span.end, in.lastOffset), " *")
+              patch(source, Span(t.span.end, in.lastOffset), "*")
           else if opStack.nonEmpty then
             report.errorOrMigrationWarning(
               em"""`_*` can be used only for last argument of method application.

tests/rewrites/rewrites3x.check

@@ -0,0 +1,10 @@
+import scala.{collection as coll, runtime as _, *}
+import coll.*
+
+def f(xs: Int*) = xs.sum
+def test =
+  f(List(1, 2, 3)*)
+
+def g = { implicit (x: Int) =>
+  x + 1
+}