Change error message

Author: nicolasstucki

compiler/src/dotty/tools/dotc/typer/Checking.scala

@@ -504,9 +504,9 @@ object Checking {
             if (param.is(Mutable))
               ctx.error(ValueClassParameterMayNotBeAVar(clazz, param), param.pos)
             if (param.info.isPhantom)
-              ctx.error("value class first parameter must not be phantom", param.pos)
+              ctx.error("First parameter of value class must not be phantom", param.pos)
             else if (param.is(Unused))
-              ctx.error("value class first parameter cannot be `unused`", param.pos)
+              ctx.error("First parameter of value class cannot be `unused`", param.pos)
             else {
               for (p <- params if !(p.info.isPhantom || p.is(Unused)))
                 ctx.error("value class can only have one non `unused` parameter", p.pos)