Update default_java_toolchain.bzl to match Bazel@head version.

toolchains/default_java_toolchain.bzl

diff --git a/toolchains/default_java_toolchain.bzl b/toolchains/default_java_toolchain.bzl
index e5f4443..343adaf 100644
--- a/toolchains/default_java_toolchain.bzl
+++ b/toolchains/default_java_toolchain.bzl
@@ -1,4 +1,4 @@
-# Copyright 2021 The Bazel Authors. All rights reserved.
+# Copyright 2022 The Bazel Authors. All rights reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -42,19 +42,15 @@
     "-Dsun.io.useCanonCaches=false",
 ]
 
-JDK9_JVM_OPTS = BASE_JDK9_JVM_OPTS + [
-    # override the javac in the JDK.
-    "--patch-module=java.compiler=$(location @remote_java_tools//:java_compiler_jar)",
-    "--patch-module=jdk.compiler=$(location @remote_java_tools//:jdk_compiler_jar)",
-]
+JDK9_JVM_OPTS = BASE_JDK9_JVM_OPTS
 
 DEFAULT_JAVACOPTS = [
     "-XDskipDuplicateBridges=true",
     "-XDcompilePolicy=simple",
     "-g",
     "-parameters",
-    # https://github.com/bazelbuild/java_tools/issues/51#issuecomment-927940699
-    "-XepOpt:ReturnValueIgnored:ObjectMethods=false",
+    # https://github.com/bazelbuild/bazel/issues/15219
+    "-Xep:ReturnValueIgnored:OFF",
 ]
 
 # java_toolchain parameters without specifying javac, java.compiler,
@@ -90,10 +86,6 @@
         # Turbine is not a worker and parallel GC is faster for short-lived programs.
         "-XX:+UseParallelOldGC",
     ],
-    tools = [
-        "@remote_java_tools//:java_compiler_jar",
-        "@remote_java_tools//:jdk_compiler_jar",
-    ],
     java_runtime = "//toolchains:remote_jdk11",
 )
 
@@ -129,10 +121,6 @@
         # Turbine is not a worker and parallel GC is faster for short-lived programs.
         "-XX:+UseParallelOldGC",
     ],
-    tools = [
-        "@remote_java_tools//:java_compiler_jar",
-        "@remote_java_tools//:jdk_compiler_jar",
-    ],
     ijar = ["//toolchains:ijar_prebuilt_binary"],
     singlejar = ["//toolchains:prebuilt_singlejar"],
     java_runtime = "//toolchains:remote_jdk11",
@@ -148,10 +136,6 @@
         # Turbine is not a worker and parallel GC is faster for short-lived programs.
         "-XX:+UseParallelOldGC",
     ],
-    tools = [
-        "@remote_java_tools//:java_compiler_jar",
-        "@remote_java_tools//:jdk_compiler_jar",
-    ],
     ijar = ["@remote_java_tools//:ijar_cc_binary"],
     singlejar = ["@remote_java_tools//:singlejar_cc_bin"],
     java_runtime = "//toolchains:remote_jdk11",
@@ -206,16 +190,7 @@
 def _bootclasspath_impl(ctx):
     host_javabase = ctx.attr.host_javabase[java_common.JavaRuntimeInfo]
 
-    # explicitly list output files instead of using TreeArtifact to work around
-    # https://github.com/bazelbuild/bazel/issues/6203
-    classes = [
-        "DumpPlatformClassPath.class",
-    ]
-
-    class_outputs = [
-        ctx.actions.declare_file("%s_classes/%s" % (ctx.label.name, clazz))
-        for clazz in classes
-    ]
+    class_dir = ctx.actions.declare_directory("%s_classes" % ctx.label.name)
 
     args = ctx.actions.args()
     args.add("-source")
@@ -226,20 +201,20 @@
     args.add("-cp")
     args.add("%s/lib/tools.jar" % host_javabase.java_home)
     args.add("-d")
-    args.add(class_outputs[0].dirname)
+    args.add_all([class_dir], expand_directories = False)
     args.add(ctx.file.src)
 
     ctx.actions.run(
         executable = "%s/bin/javac" % host_javabase.java_home,
         mnemonic = "JavaToolchainCompileClasses",
         inputs = [ctx.file.src] + ctx.files.host_javabase,
-        outputs = class_outputs,
+        outputs = [class_dir],
         arguments = [args],
     )
 
     bootclasspath = ctx.outputs.output_jar
 
-    inputs = class_outputs + ctx.files.host_javabase
+    inputs = [class_dir] + ctx.files.host_javabase
 
     args = ctx.actions.args()
     args.add("-XX:+IgnoreUnrecognizedVMOptions")
@@ -248,8 +223,9 @@
     args.add("--add-exports=jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED")
     args.add_joined(
         "-cp",
-        [class_outputs[0].dirname, "%s/lib/tools.jar" % host_javabase.java_home],
+        [class_dir, "%s/lib/tools.jar" % host_javabase.java_home],
         join_with = ctx.configuration.host_path_separator,
+        expand_directories = False,
     )
     args.add("DumpPlatformClassPath")
     args.add(bootclasspath)
@@ -277,7 +253,6 @@
             cfg = "exec",
             providers = [java_common.JavaRuntimeInfo],
         ),
-        "output_jar": attr.output(mandatory = True),
         "src": attr.label(
             cfg = "exec",
             allow_single_file = True,
@@ -285,6 +260,7 @@
         "target_javabase": attr.label(
             providers = [java_common.JavaRuntimeInfo],
         ),
+        "output_jar": attr.output(mandatory = True),
     },
 )