Reland [Syntax] Add minimal TableGen for syntax nodes. NFC

This reverts commit 09c6259d6d0eb51b282f6c3a28052a8146bc095b.
(Fixed side-effecting code being buried in an assert)

2 files changed, 4 insertions, 20 deletions

diff --git a/clang/lib/Tooling/Syntax/Nodes.cpp b/clang/lib/Tooling/Syntax/Nodes.cpp
index b4d1cfd..0be9f1f 100644
--- a/clang/lib/Tooling/Syntax/Nodes.cpp
+++ b/clang/lib/Tooling/Syntax/Nodes.cpp
@@ -630,3 +630,7 @@ syntax::ParametersAndQualifiers::getTrailingReturn() {
   return cast_or_null<syntax::TrailingReturnType>(
       findChild(syntax::NodeRole::TrailingReturn));
 }
+
+#define NODE(Kind, Parent)                                                     \
+  static_assert(sizeof(syntax::Kind) > 0, "Missing Node subclass definition");
+#include "clang/Tooling/Syntax/Nodes.inc"
diff --git a/clang/lib/Tooling/Syntax/Tree.cpp b/clang/lib/Tooling/Syntax/Tree.cpp
index fca2be5..07ee13e3 100644
--- a/clang/lib/Tooling/Syntax/Tree.cpp
+++ b/clang/lib/Tooling/Syntax/Tree.cpp
@@ -52,10 +52,6 @@ syntax::Leaf::Leaf(const syntax::Token *Tok) : Node(NodeKind::Leaf), Tok(Tok) {
   assert(Tok != nullptr);
 }
 
-bool syntax::Leaf::classof(const Node *N) {
-  return N->getKind() == NodeKind::Leaf;
-}
-
 syntax::Node::Node(NodeKind Kind)
     : Parent(nullptr), NextSibling(nullptr), PreviousSibling(nullptr),
       Kind(static_cast<unsigned>(Kind)), Role(0), Original(false),
@@ -71,10 +67,6 @@ void syntax::Node::setRole(NodeRole NR) {
   this->Role = static_cast<unsigned>(NR);
 }
 
-bool syntax::Tree::classof(const Node *N) {
-  return N->getKind() > NodeKind::Leaf;
-}
-
 void syntax::Tree::appendChildLowLevel(Node *Child, NodeRole Role) {
   assert(Child->getRole() == NodeRole::Detached);
   assert(Role != NodeRole::Detached);
@@ -345,18 +337,6 @@ const syntax::Node *syntax::Tree::findChild(NodeRole R) const {
   return nullptr;
 }
 
-bool syntax::List::classof(const syntax::Node *N) {
-  switch (N->getKind()) {
-  case syntax::NodeKind::NestedNameSpecifier:
-  case syntax::NodeKind::CallArguments:
-  case syntax::NodeKind::ParameterDeclarationList:
-  case syntax::NodeKind::DeclaratorList:
-    return true;
-  default:
-    return false;
-  }
-}
-
 std::vector<syntax::List::ElementAndDelimiter<syntax::Node>>
 syntax::List::getElementsAsNodesAndDelimiters() {
   if (!getFirstChild())