[GR-12330] Depend on the ANTLR version that Truffle pulls in.

PullRequest: graalpython/261

Author: timfel

ci.jsonnet

@@ -70,7 +70,7 @@
       "git": ">=1.8.3",
       "mercurial": ">=3.2.4",
       "gcc": "==4.9.1",
-      "llvm": ">=4.0",
+      "llvm": "==4.0.1",
       "python": "==3.4.1",
       "libffi": ">=3.2.1",
       "bzip2": ">=1.0.6",