Work around polly linking issue in LLVM 10 tests

TheDan64 · TheDan64 · commit cb6e10f0bd25 · 2020-08-01T11:34:31.000-04:00
diff --git a/.travis.yml b/.travis.yml
@@ -195,6 +195,7 @@ matrix:
           packages:
             - *BASE_PACKAGES
             - llvm-10-dev
+            - libclang-common-10-dev
       rust: 1.39.0
       dist: bionic
     - deploy: # Documentation build; Only latest supported LLVM version for now
