SI-9847 Nuance pure expr statement warning

Clarify the current warning, which means that an expression
split over multiple lines may not be parsed as naively expected.

When typing a block, attempt minor nuance. For instance, a
single expression is not in need of parens. Try to avoid
duplicate warnings for expressions that were adapted away
from result position.

1 files changed, 3 insertions, 3 deletions

diff --git a/test/files/neg/t1181.check b/test/files/neg/t1181.check
index 13b73d5381..a9c102853d 100644
--- a/test/files/neg/t1181.check
+++ b/test/files/neg/t1181.check
@@ -1,10 +1,10 @@
-t1181.scala:8: warning: a pure expression does nothing in statement position; you may be omitting necessary parentheses
-     case (Nil, Nil) => map
-                        ^
 t1181.scala:9: error: type mismatch;
  found   : scala.collection.immutable.Map[Symbol,Symbol]
  required: Symbol
      _ => buildMap(map.updated(keyList.head, valueList.head), keyList.tail, valueList.tail)
                   ^
+t1181.scala:8: warning: a pure expression does nothing in statement position; multiline expressions might require enclosing parentheses
+     case (Nil, Nil) => map
+                        ^
 one warning found
 one error found