gnu: node: Build against libuv@1.19.

* gnu/packages/libevent.scm (libuv-1.19): New public variable.
* gnu/packages/node.scm (node)[inputs]: Change LIBUV to LIBUV-1.19.

gnu/packages/libevent.scm

@@ -152,6 +152,19 @@ resolution, asynchronous file system operations, and threading primitives.")
     ;; details.  Documentation is CC-BY 4.0 as of 1.12.0; see 'LICENSE-docs'.
     (license (list expat cc-by4.0))))
 
+;; This version is required for Node versions < 10.
+(define-public libuv-1.19
+  (package
+    (inherit libuv)
+    (version "1.19.2")
+    (source (origin
+              (method url-fetch)
+              (uri (string-append "https://dist.libuv.org/dist/v" version
+                                  "/libuv-v" version ".tar.gz"))
+              (sha256
+               (base32
+                "1msk9ac1z69whww88ibrwjqkd1apdla6l77cm2fwy5kigq0z5g3w"))))))
+
 (define-public perl-anyevent
   (package
     (name "perl-anyevent")

gnu/packages/node.scm

@@ -184,7 +184,7 @@
      `(("c-ares" ,c-ares)
        ("http-parser" ,http-parser)
        ("icu4c" ,icu4c)
-       ("libuv" ,libuv)
+       ("libuv" ,libuv-1.19)
        ("nghttp2" ,nghttp2 "lib")
        ("openssl" ,openssl)
        ("zlib" ,zlib)))