remove unnecessay conds for nilable strings/seqs

lib/std/private/miscdollars.nim

@@ -26,7 +26,7 @@ template tupleObjectDollar*[T: tuple | object](result: var string, x: T) =
       result.add(": ")
     count.inc
     when compiles($value):
-      when value isnot string and value isnot seq and compiles(value.isNil):
+      when compiles(value.isNil):
         if value.isNil: result.add "nil"
         else: result.addQuoted(value)
       else:

lib/system/dollars.nim

@@ -106,7 +106,7 @@ proc collectionToString[T](x: T, prefix, separator, suffix: string): string =
     else:
       result.add(separator)
 
-    when value isnot string and value isnot seq and compiles(value.isNil):
+    when compiles(value.isNil):
       # this branch should not be necessary
       if value.isNil:
         result.add "nil"