Ensure g++-7 is first on the PATH before calling CI-list_unsupported.sh to avoid clash with gnat g++

Author: chrisr-diffblue

.travis.yml

@@ -87,7 +87,14 @@ script:
   #run the tests
   - (cd testsuite/gnat2goto; ./testsuite.py --timeout 60 --diffs --enable-color -j 2 )
   - gnat2goto/install/bin/unit_tests
-  - (gnat --version; cd ${TRAVIS_BUILD_DIR}/experiments; ./CI-list_unsupported.sh )
+  - |
+    #run CI-list_unsupported, making sure g++-7 is first on the PATH
+    ( set -euo pipefail
+      gnat --version
+      cd ${TRAVIS_BUILD_DIR}/experiments
+      export PATH=${TRAVIS_BUILD_DIR}/bin:${PATH}
+      ./CI-list_unsupported.sh
+    )
 
 before_cache:
   - ccache -s