Add antlr4-runtime (chiseltest runtime dep)

Change-Id: I1c6d66febf42d94d24672a93b137d4f423a4c9bf

rules/chisel.bzl

diff --git a/rules/chisel.bzl b/rules/chisel.bzl
index 1102ece..b22a008 100644
--- a/rules/chisel.bzl
+++ b/rules/chisel.bzl
@@ -77,6 +77,7 @@
             "@org_scalatest_scalatest//jar",
             "@edu_berkeley_cs_firrtl//jar",
             "@edu_berkeley_cs_chiseltest//jar",
+            "@org_antlr_antlr4_runtime//jar",
         ] + deps,
         scalacopts = SCALA_COPTS,
         visibility = visibility,

rules/deps.bzl

diff --git a/rules/deps.bzl b/rules/deps.bzl
index dbc2d6c..0945121 100644
--- a/rules/deps.bzl
+++ b/rules/deps.bzl
@@ -173,6 +173,14 @@
         licenses = ["notice"],
     )
 
+    # Antlr4
+    scala_maven_import_external(
+        name = "org_antlr_antlr4_runtime",
+        artifact = "org.antlr:antlr4-runtime:%s" % "4.13.1",
+        server_urls = default_maven_server_urls(),
+        licenses = ["notice"],
+    )
+
 def kelvin_deps():
     """Full kelvin dependent repositories