Make skylark_semantics library visible to Copybara

RELNOTES: None.
PiperOrigin-RevId: 234987943

src/main/java/com/google/devtools/build/lib/BUILD

diff --git a/src/main/java/com/google/devtools/build/lib/BUILD b/src/main/java/com/google/devtools/build/lib/BUILD
index 211fa48..7eeea00 100644
--- a/src/main/java/com/google/devtools/build/lib/BUILD
+++ b/src/main/java/com/google/devtools/build/lib/BUILD
@@ -412,6 +412,7 @@
     srcs = [
         "syntax/StarlarkSemantics.java",
     ],
+    visibility = ["//visibility:public"],  # needed by Copybara
     deps = [
         "//third_party:auto_value",
         "//third_party:guava",