tarsnap 1.30

- Compilation hangs with LLVM.
- Homebrew/homebrew#4693 claims it was due to SSE2 but even w/o it still hangs.

- add 'fails_with_llvm'
- bring back '--enable-sse2'

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Formula/tarsnap.rb

@@ -1,14 +1,17 @@
 require 'formula'
 
 class Tarsnap < Formula
-  url 'https://www.tarsnap.com/download/tarsnap-autoconf-1.0.29.tgz'
+  url 'https://www.tarsnap.com/download/tarsnap-autoconf-1.0.30.tgz'
   homepage 'http://www.tarsnap.com/'
-  sha256 '747510459e4af0ebbb6e267c159aa019f9337d1e07bd9a94f1aa1498081b7598'
+  sha256 'ad663922064a98bce9c085a53ecd83eb839457b49d7cd22cff7c069e9b7e522e'
 
   depends_on 'lzma' => :optional
 
+  fails_with_llvm "Compilation hangs."
+
   def install
     system "./configure", "--disable-dependency-tracking",
+                          "--enable-sse2",
                           "--prefix=#{prefix}",
                           "--sysconfdir=#{etc}"
     system "make install"