src: add include for standalone compile

- Include algorithm header in js_native_api_v8.cc since std::min
  requires it.
- Add comments to js_native_api_v8_internals.h for NAPI_VERSION

PR-URL: #24498
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gabriel Schulhof <gabriel.schulhof@intel.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>

src/js_native_api_v8.cc

@@ -1,5 +1,6 @@
 #include <limits.h>  // INT_MAX
 #include <cmath>
+#include <algorithm>
 #define NAPI_EXPERIMENTAL
 #include "js_native_api_v8.h"
 #include "js_native_api.h"

src/js_native_api_v8_internals.h

@@ -4,11 +4,14 @@
 // The V8 implementation of N-API, including `js_native_api_v8.h` uses certain
 // idioms which require definition here. For example, it uses a variant of
 // persistent references which need not be reset in the constructor. It is the
-// responsibility of this file to define these idioms.
+// responsibility of this file to define these idioms. Optionally, this file
+// may also define `NAPI_VERSION` and set it to the version of N-API to be
+// exposed.
 
 // In the case of the Node.js implementation of N-API some of the idioms are
 // imported directly from Node.js by including `node_internals.h` below. Others
-// are bridged to remove references to the `node` namespace.
+// are bridged to remove references to the `node` namespace. `node_version.h`,
+// included below, defines `NAPI_VERSION`.
 
 #include "node_version.h"
 #include "env.h"