Merge pull request #4218 from robstoll/patch-5

fix spelling, classes instead of lasses

Author: allanrenucci

compiler/src/dotty/tools/dotc/ast/Desugar.scala

@@ -50,7 +50,7 @@ object desugar {
    */
   class DerivedFromParamTree(suffix: String) extends DerivedTypeTree {
 
-    /** Make sure that for all enclosing module classes their companion lasses
+    /** Make sure that for all enclosing module classes their companion classes
      *  are completed. Reason: We need the constructor of such companion classes to
      *  be completed so that OriginalSymbol attachments are pushed to DerivedTypeTrees
      *  in apply/unapply methods.