improvement for 'unused import' warnings

compiler/semtempl.nim

@@ -80,6 +80,7 @@ proc symChoice(c: PContext, n: PNode, s: PSym, r: TSymChoiceRule;
     while a != nil:
       if a.kind != skModule and (not isField or sfGenSym notin s.flags):
         incl(a.flags, sfUsed)
+        markOwnerModuleAsUsed(c, a)
         addSon(result, newSymNode(a, info))
         onUse(info, a)
       a = nextOverloadIter(o, c, n)

compiler/sigmatch.nim

@@ -108,6 +108,7 @@ const
   isNilConversion = isConvertible # maybe 'isIntConv' fits better?
 
 proc markUsed*(c: PContext; info: TLineInfo, s: PSym)
+proc markOwnerModuleAsUsed*(c: PContext; s: PSym)
 
 template hasFauxMatch*(c: TCandidate): bool = c.fauxMatch != tyNone