Fixup gcc symlink needed for regression tests on clang builds

Author: chrisr-diffblue

.travis.yml

@@ -144,7 +144,7 @@ jobs:
             - parallel
             - libc6-dev-i386
       before_install:
-        - mkdir bin ; ln -s /usr/bin/clang-3.7 bin/gcc
+        - mkdir bin ; ln -s /usr/bin/gcc-5 bin/gcc
         - export CCACHE_CPP2=yes
       # env: COMPILER=clang++-3.7 SAN_FLAGS="-fsanitize=undefined -fno-sanitize-recover=undefined,integer -fno-omit-frame-pointer"
       env: