add portability test for gcc7.2
diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index 6b27d6f..b751bf9 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -507,6 +507,8 @@
             return ('jessie', self._gcc_make_options(version_suffix='-4.8'))
         elif compiler == 'gcc5.3':
             return ('ubuntu1604', [])
+        elif compiler == 'gcc7.2':
+            return ('ubuntu1710', [])
         elif compiler == 'gcc_musl':
             return ('alpine', [])
         elif compiler == 'clang3.4':
@@ -1327,8 +1329,8 @@
 argp.add_argument(
     '--compiler',
     choices=[
-        'default', 'gcc4.4', 'gcc4.6', 'gcc4.8', 'gcc4.9', 'gcc5.3', 'gcc_musl',
-        'clang3.4', 'clang3.5', 'clang3.6', 'clang3.7', 'python2.7',
+        'default', 'gcc4.4', 'gcc4.6', 'gcc4.8', 'gcc4.9', 'gcc5.3', 'gcc7.2',
+        'gcc_musl', 'clang3.4', 'clang3.5', 'clang3.6', 'clang3.7', 'python2.7',
         'python3.4', 'python3.5', 'python3.6', 'pypy', 'pypy3', 'python_alpine',
         'all_the_cpythons', 'electron1.3', 'electron1.6', 'coreclr', 'cmake',
         'cmake_vs2015', 'cmake_vs2017'