gnu: ungoogled-chromium: Build against ICU 64.

* gnu/packages/icu4c.scm (icu4c-64): New public variable.
* gnu/packages/chromium.scm (ungoogled-chromium)[inputs]: Change ICU4C to ICU4C-64.

gnu/packages/chromium.scm

@@ -714,7 +714,11 @@ from forcing GEXP-PROMISE."
        ("glib" ,glib)
        ("gtk+" ,gtk+)
        ("harfbuzz" ,harfbuzz)
-       ("icu4c" ,icu4c)
+
+       ;; Build against ICU 64 to prevent a localization problem in version 75
+       ;; and later: <https://github.com/Eloston/ungoogled-chromium/issues/778>.
+       ("icu4c" ,icu4c-64)
+
        ("jsoncpp" ,jsoncpp)
        ("lcms" ,lcms)
        ("libevent" ,libevent)

gnu/packages/icu4c.scm

@@ -4,6 +4,7 @@
 ;;; Copyright © 2016, 2017 Efraim Flashner <efraim@flashner.co.il>
 ;;; Copyright © 2017 Clément Lassieur <clement@lassieur.org>
 ;;; Copyright © 2017 Ricardo Wurmus <rekado@elephly.net>
+;;; Copyright © 2019 Marius Bakke <mbakke@fastmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -23,6 +24,7 @@
 (define-module (gnu packages icu4c)
   #:use-module (gnu packages)
   #:use-module (gnu packages perl)
+  #:use-module (gnu packages python)
   #:use-module (guix licenses)
   #:use-module (guix packages)
   #:use-module (guix download)
@@ -81,6 +83,22 @@ C/C++ part.")
    (license x11)
    (home-page "http://site.icu-project.org/")))
 
+(define-public icu4c-64
+  (package
+    (inherit icu4c)
+    (version "64.2")
+    (source (origin
+              (inherit (package-source icu4c))
+              (uri (string-append
+                    "http://download.icu-project.org/files/icu4c/" version "/icu4c-"
+                    (string-map (lambda (x) (if (char=? x #\.) #\_ x)) version)
+                    "-src.tgz"))
+              (sha256
+               (base32 "0v0xsf14xwlj125y9fd8lrhsaych4d8liv8gr746zng6g225szb2"))))
+    (native-inputs
+     `(;; For tests.
+       ("python" ,python)))))
+
 (define-public java-icu4j
   (package
     (name "java-icu4j")