Rename Skylark to Starlark in user-visible strings

https://blog.bazel.build/2018/08/17/starlark.html

RELNOTES: None.
PiperOrigin-RevId: 218669928
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/BuiltinFunction.java b/src/main/java/com/google/devtools/build/lib/syntax/BuiltinFunction.java
index 70d2bbf..bfdc795 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/BuiltinFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/BuiltinFunction.java
@@ -225,7 +225,7 @@
         String.format(
             "%s%s (%s)\n"
                 + "while calling %s with args %s\n"
-                + "Java parameter types: %s\nSkylark type checks: %s",
+                + "Java parameter types: %s\nStarlark type checks: %s",
             (loc == null) ? "" : loc + ": ",
             Arrays.asList(args),
             e.getClass().getName(),