Remove trailing spaces in printing class body

Author: liufengyun

compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala

@@ -776,7 +776,7 @@ class RefinedPrinter(_ctx: Context) extends PlainPrinter(_ctx) {
       params ::: rest
     } else impl.body
 
-    val bodyText = " {" ~~ selfText ~~ toTextGlobal(primaryConstrs ::: body, "\n") ~ "}"
+    val bodyText = " {" ~~ selfText ~ toTextGlobal(primaryConstrs ::: body, "\n") ~ "}"
 
     prefix ~
     keywordText(" extends").provided(!ofNew && impl.parents.nonEmpty) ~~ parentsText ~

tests/printing/i620.check

@@ -1,3 +1,4 @@
+result of tests/printing/i620.scala after frontend:
 package O {
   package O.A {
     class D() extends Object() {
@@ -26,4 +27,4 @@ package O {
       val g: Int = 0
     }
   }
-}
+}