tests/plugin/rtl: disable prior to gcc 5

Author: davidmalcolm

run-test-suite.py

@@ -747,6 +747,10 @@ def exclude_tests_below(path):
     exclude_test('tests/plugin/callgraph')
     exclude_test('tests/plugin/rtl')
 
+# Tests that are over-specified and only work for GCC 5 and later:
+if GCC_VERSION < 5000:
+    exclude_test('tests/plugin/rtl')
+
 # Tests that are over-specified and only work for GCC 6 and later:
 if GCC_VERSION < 6000:
     exclude_test('tests/examples/find-global-state')