Merge version 6.4.0-3+rpi1 and 6.4.0-4 to produce 6.4.0-4+rpi1

diff --cc debian/changelog
index 48806e9e04646443b59bbc2cc0ec31d5449c9fc4,1cac64071ddc95867482ced54f3e0ea6b39be09c..5cb982e335729ad16f89aa3e60534bfca840add6
--- 1/debian/changelog
--- 2/debian/changelog
+++ b/debian/changelog
@@@ -1,6 -1,12 +1,16 @@@
- gcc-6 (6.4.0-3+rpi1) buster-staging; urgency=medium
++gcc-6 (6.4.0-4+rpi1) buster-staging; urgency=medium
 +
-  -- Raspbian forward porter <root@raspbian.org>  Fri, 18 Aug 2017 14:47:38 +0000
++ -- Raspbian forward porter <root@raspbian.org>  Fri, 01 Sep 2017 05:31:53 +0000
++
+ gcc-6 (6.4.0-4) unstable; urgency=medium
+ 
+   * Update to SVN 20170820 (r251205) from the gcc-6-branch.
+     - Fix PR target/81894 (x86), PR target/81861 (x86),
+       PR tree-optimization/81354, PR c++/71570.
+   * Don't build the gc enabled libobjc for cross compilers. Closes: #872301.
+   * Fix hangs w/ asan binaries on arm64 (Dann Frazier). LP: #1709727.
+ 
+  -- Matthias Klose <doko@debian.org>  Sun, 20 Aug 2017 17:23:10 +0200
  
  gcc-6 (6.4.0-3) unstable; urgency=medium
  

diff --cc debian/rules.defs
Simple merge