Pass --batch to gdb

In one of my travis builds, I was surprised to find that the gdb pager was in use and caused travis to time out. Adding `--batch` to the gdb invocation will disable the pager. Note that the `-ex q` is retained, to make sure gdb exits with status 0, just in case `set -e` is in effect somehow.
rust-lang · bors · Sep 21, 2018 · Jul 29, 2018 · Jul 29, 2018 · Jul 29, 2018
commit e2ff97a14d832b6814292d54fcea155f5d1905bc
diff --git a/.travis.yml b/.travis.yml
@@ -301,7 +301,7 @@ after_failure:
       EXE=$(echo $CORE | sed 's|obj/cores/core\.[0-9]*\.!checkout!\(.*\)|\1|;y|!|/|');
       if [ -f "$EXE" ]; then
         printf travis_fold":start:crashlog\n\033[31;1m%s\033[0m\n" "$CORE";
-        gdb -q -c "$CORE" "$EXE"
+        gdb --batch -q -c "$CORE" "$EXE"
           -iex 'set auto-load off'
           -iex 'dir src/'
           -iex 'set sysroot .'