fix dot calls with resolved symbols in templates (#22076)

* fix dot calls with resolved symbols in templates

* make old code work

* fix custom number literals test

* remove leftover debug marker

* enable "bug 9" test too

* fix renderer, add test for #7085

compiler/ast.nim

@@ -1128,11 +1128,10 @@ const
 
 proc getPIdent*(a: PNode): PIdent {.inline.} =
   ## Returns underlying `PIdent` for `{nkSym, nkIdent}`, or `nil`.
-  # xxx consider whether also returning the 1st ident for {nkOpenSymChoice, nkClosedSymChoice}
-  # which may simplify code.
   case a.kind
   of nkSym: a.sym.name
   of nkIdent: a.ident
+  of nkOpenSymChoice, nkClosedSymChoice: a.sons[0].sym.name
   else: nil
 
 const

compiler/renderer.nim

@@ -379,6 +379,7 @@ proc atom(g: TSrcGen; n: PNode): string =
   of nkEmpty: result = ""
   of nkIdent: result = n.ident.s
   of nkSym: result = n.sym.name.s
+  of nkClosedSymChoice, nkOpenSymChoice: result = n[0].sym.name.s
   of nkStrLit: result = ""; result.addQuoted(n.strVal)
   of nkRStrLit: result = "r\"" & replace(n.strVal, "\"", "\"\"") & '\"'
   of nkTripleStrLit: result = "\"\"\"" & n.strVal & "\"\"\""

compiler/semtempl.nim

@@ -561,6 +561,14 @@ proc semTemplBody(c: var TemplCtx, n: PNode): PNode =
       inc c.noGenSym
       result[1] = semTemplBody(c, n[1])
       dec c.noGenSym
+      if result[1].kind == nkSym and result[1].sym.kind in routineKinds:
+        # prevent `dotTransformation` from rewriting this node to `nkIdent`
+        # by making it a symchoice
+        # in generics this becomes `nkClosedSymChoice` but this breaks code
+        # as the old behavior here was that this became `nkIdent`
+        var choice = newNodeIT(nkOpenSymChoice, n[1].info, newTypeS(tyNone, c.c))
+        choice.add result[1]
+        result[1] = choice
     else:
       result = semTemplBodySons(c, n)
   of nkExprColonExpr, nkExprEqExpr: