Cleanup some small remnants of the J2CL/GWT builds of the compiler

PiperOrigin-RevId: 713037488

Author: lauraharker

src/com/google/javascript/jscomp/graph/StandardUnionFind.java

@@ -20,7 +20,6 @@
 import static com.google.common.collect.Iterators.filter;
 import static com.google.common.collect.Multimaps.asMap;
 
-import com.google.common.annotations.GwtCompatible;
 import com.google.common.base.Objects;
 import com.google.common.base.Predicate;
 import com.google.common.collect.ImmutableList;
@@ -46,7 +45,6 @@
  *
  * @param <E> element type
  */
-@GwtCompatible
 public class StandardUnionFind<E> implements Serializable, UnionFind<E> {
 
   /** All values with the same root node are in the same equivalence set. */

src/com/google/javascript/rhino/typed_ast/BUILD.bazel

@@ -31,9 +31,3 @@ java_proto_library(
     name = "typed_ast_java_proto",
     deps = [":typed_ast_proto"],
 )
-
-# TODO: Reenable once j2cl_proto_library is working again.
-# j2cl_proto_library(
-#     name = "typed_ast_j2cl_proto",
-#     deps = [":typed_ast_proto"],
-# )

test/com/google/javascript/jscomp/PeepholeReplaceKnownMethodsTest.java

@@ -67,7 +67,6 @@ public void setUp() throws Exception {
     useTypes = true;
     disableTypeCheck();
     enableNormalize();
-    disableMultistageCompilation(); // this test runs under J2CL
   }
 
   @Override