Swift: split generated C++ code into .h and .cpp

swift/codegen/templates/cpp_classes_h.mustache

@@ -0,0 +1,42 @@
+// generated by {{generator}} from {{source}}
+// clang-format off
+#pragma once
+
+#include <iostream>
+#include <optional>
+#include <vector>
+
+#include "swift/extractor/trap/TrapLabel.h"
+#include "swift/extractor/trap/TrapTagTraits.h"
+#include "./TrapEntries.h"
+
+namespace codeql {
+{{#classes}}
+
+struct {{name}}{{#has_bases}} : {{#bases}}{{^first}}, {{/first}}{{ref.name}}{{/bases}}{{/has_bases}} {
+  {{#final}}
+  explicit {{name}}(TrapLabel<{{name}}Tag> id) : id{id} {}
+
+  TrapLabel<{{name}}Tag> id{};
+  {{/final}}
+  {{#fields}}
+  {{type}} {{field_name}}{};
+  {{/fields}}
+  {{#final}}
+
+  friend std::ostream& operator<<(std::ostream& out, const {{name}}& x) {
+    x.emit(out);
+    return out;
+  }
+  {{/final}}
+
+ protected:
+  void emit({{^final}}TrapLabel<{{name}}Tag> id, {{/final}}std::ostream& out) const;
+};
+
+template <>
+struct detail::ToTrapClassFunctor<{{name}}Tag> {
+  using type = {{name}};
+};
+{{/classes}}
+}