Move DOM parsing into concrete interface implementation

src/fallback/implementation.cpp

@@ -0,0 +1,25 @@
+#include "simdjson.h"
+#include "fallback/implementation.h"
+#include "fallback/dom_parser_implementation.h"
+
+TARGET_HASWELL
+
+namespace simdjson {
+namespace fallback {
+
+WARN_UNUSED error_code implementation::create_dom_parser_implementation(
+  size_t capacity,
+  size_t max_depth,
+  std::unique_ptr<internal::dom_parser_implementation>& dst
+) const noexcept {
+  dst.reset( new (std::nothrow) dom_parser_implementation() );
+  if (!dst) { return MEMALLOC; }
+  dst->set_capacity(capacity);
+  dst->set_max_depth(max_depth);
+  return SUCCESS;
+}
+
+} // namespace fallback
+} // namespace simdjson
+
+UNTARGET_REGION