unify tuple expressions (#13793)

* unify tuple expressions

* fix test

* fix test

* apply feedback

* Handle empty tuples

* Fix rendering named unary tuple

* Protect static NimNode against stripping

* Slightly less hacky

* Revert "Slightly less hacky"

This reverts commit 170c5aec0addc029f637afbc948700ca006b7942.

* Slightly less hacky

* Cleanup

* Fix test

* Fix another test

* Add condsym

* Rebase fallout

* changelog: Move from compiler changes to language changes

* Add stricter tests

* Add empty tuple example to doc/astspec

* Fix test

Co-authored-by: Clyybber <darkmine956@gmail.com>

compiler/vm.nim

@@ -2228,6 +2228,12 @@ proc prepareVMValue(arg: PNode): PNode =
   if arg.kind in nkLiterals:
     return arg
 
+  if arg.kind == nkExprColonExpr and arg[0].typ != nil and
+     arg[0].typ.sym != nil and arg[0].typ.sym.magic == mPNimrodNode:
+    # Poor mans way of protecting static NimNodes
+    # XXX: Maybe we need a nkNimNode?
+    return arg
+
   result = copyNode(arg)
   if arg.kind == nkTupleConstr:
     for child in arg: