fix #13515 [backport] (#20315)

(cherry picked from commit 58e6d439d8)

compiler/semtempl.nim

@@ -250,8 +250,14 @@ proc semTemplSymbol(c: PContext, n: PNode, s: PSym; isField: bool): PNode =
   of skUnknown:
     # Introduced in this pass! Leave it as an identifier.
     result = n
-  of OverloadableSyms-{skEnumField}:
+  of OverloadableSyms-{skEnumField, skTemplate, skMacro}:
     result = symChoice(c, n, s, scOpen, isField)
+  of skTemplate, skMacro:
+    result = symChoice(c, n, s, scOpen, isField)
+    if result.kind == nkSym:
+      # template/macro symbols might need to be semchecked again
+      # prepareOperand etc don't do this without setting the type to nil
+      result.typ = nil
   of skGenericParam:
     if isField and sfGenSym in s.flags: result = n
     else: result = newSymNodeTypeDesc(s, c.idgen, n.info)

tests/template/t13515.nim

@@ -0,0 +1,16 @@
+discard """
+  action: compile
+"""
+
+template test: bool = true
+
+# compiles:
+if not test:
+  echo "wtf"
+
+# does not compile:
+template x =
+  if not test:
+    echo "wtf"
+
+x