fix #20002 (#20004)

While this fix seems innocent,
this unlocks the hidden behavior of
method calls not being able to call
gensym'ed routines inside templates.

(cherry picked from commit f35c9cf73d)

compiler/semtempl.nim

@@ -78,7 +78,7 @@ proc symChoice(c: PContext, n: PNode, s: PSym, r: TSymChoiceRule;
     result = newNodeIT(kind, info, newTypeS(tyNone, c))
     a = initOverloadIter(o, c, n)
     while a != nil:
-      if a.kind != skModule and (not isField or sfGenSym notin s.flags):
+      if a.kind != skModule and (not isField or sfGenSym notin a.flags):
         incl(a.flags, sfUsed)
         markOwnerModuleAsUsed(c, a)
         result.add newSymNode(a, info)

tests/template/tinnerouterproc.nim

@@ -0,0 +1,8 @@
+block: # #20002
+  proc bar(x: int): int = 10
+  template foo =
+    proc bar(x: int): int {.gensym.} = x + 2
+    doAssert bar(3) == 5
+    discard 3.bar # evaluates to 10 but only check if it compiles for now
+  block:
+    foo()