AST: fix build with newer clang

Elaborate the `NodeKind` typename to avoid ambiguity with `llvm::yaml::NodeKind`
and `swift::experimental_dependencies::NodeKind`.  This fixes the build with
newer compilers.

Author: compnerd

lib/AST/ExperimentalDependencies.cpp

@@ -273,8 +273,8 @@ StringRef ScalarTraits<size_t>::input(StringRef scalar, void *ctxt,
 }
 #endif
 
-void ScalarEnumerationTraits<NodeKind>::enumeration(
-    IO &io, swift::experimental_dependencies::NodeKind &value) {
+void ScalarEnumerationTraits<swift::experimental_dependencies::NodeKind>::
+    enumeration(IO &io, swift::experimental_dependencies::NodeKind &value) {
   using NodeKind = swift::experimental_dependencies::NodeKind;
   io.enumCase(value, "topLevel", NodeKind::topLevel);
   io.enumCase(value, "nominal", NodeKind::nominal);