tcl-tk: fix for Homebrew#12114 and Homebrew#12808. Reenabled the `--w…

…ith-x11` option. Without --with-x11 `brew test python` and `brew test python3` fail, and some formulae (eg pymol) break

Formula/tcl-tk.rb

@@ -21,6 +21,10 @@ class TclTk < Formula
   option "with-threads", "Build with multithreading support"
   option "without-tcllib", "Don't build tcllib (utility modules)"
   option "without-tk", "Don't build the Tk (window toolkit)"
+  option "with-x11", "Build X11-based Tk instead of Aqua-based Tk"
+
+  depends_on :x11 => :optional
+  depends_on "pkg-config" => :build if build.with? "x11"
 
   resource "tk" do
     url "https://downloads.sourceforge.net/project/tcl/Tcl/8.6.6/tk8.6.6-src.tar.gz"
@@ -54,7 +58,13 @@ def install
         args = ["--prefix=#{prefix}", "--mandir=#{man}", "--with-tcl=#{lib}"]
         args << "--enable-threads" if build.with? "threads"
         args << "--enable-64bit" if MacOS.prefer_64_bit?
-        args << "--enable-aqua=yes" << "--without-x"
+
+        if build.with? "x11"
+          args << "--with-x"
+        else
+          args << "--enable-aqua=yes"
+          args << "--without-x"
+        end
 
         cd "unix" do
           system "./configure", *args