[Bazel] Make the protobuf workspace (nearly) wildcard-buildable. (#10010)

- Add back benchmarks/datasets/BUILD.bazel to dist archive
- Change dist/build_systems.bzl to be compatible with Bazel 4.0.0.

After this, most builds can use //..., with one exception: non-Mac environments must also exclude objectivec:
`bazel build -- //... -//objectivec/...`

benchmarks/BUILD.bazel

@@ -87,7 +87,7 @@ pkg_filegroup(
     srcs = [
         ":dist_files",
         "//benchmarks/cpp:dist_files",
-        # "//benchmarks/datasets:dist_files",  # not in autotools dist
+        "//benchmarks/datasets:dist_files",  # not in autotools dist
         "//benchmarks/datasets/google_message1/proto2:dist_files",
         "//benchmarks/datasets/google_message1/proto3:dist_files",
         "//benchmarks/datasets/google_message2:dist_files",

pkg/build_systems.bzl

@@ -178,7 +178,7 @@ Output is CcFileList and/or ProtoFileList. Example:
 # fragment generator function.
 ################################################################################
 
-def _create_file_list_impl(fragment_generator):
+def _create_file_list_impl(ctx, fragment_generator):
     # `fragment_generator` is a function like:
     #     def fn(originating_rule: Label,
     #            varname: str,
@@ -191,7 +191,6 @@ def _create_file_list_impl(fragment_generator):
     # When dealing with `File` objects, the `short_path` is used to strip
     # the output prefix for generated files.
 
-    def _impl(ctx):
     out = ctx.outputs.out
 
     fragments = []
@@ -276,8 +275,6 @@ def _create_file_list_impl(fragment_generator):
 
     return [DefaultInfo(files = depset([out]))]
 
-    return _impl
-
 # Common rule attrs for rules that use `_create_file_list_impl`:
 # (note that `_header` is also required)
 _source_list_common_attrs = {
@@ -343,6 +340,9 @@ def _cmake_var_fragment(owner, varname, prefix, entries):
         entries = "\n".join(["  %s%s" % (prefix, f) for f in entries]),
     )
 
+def _cmake_file_list_impl(ctx):
+    _create_file_list_impl(ctx, _cmake_var_fragment)
+
 gen_cmake_file_lists = rule(
     doc = """
 Generates a CMake-syntax file with lists of files.
@@ -361,7 +361,7 @@ For proto_library, the following are generated:
     {libname}_hdrs: contains syntesized paths for generated C++ headers.
 
 """,
-    implementation = _create_file_list_impl(_cmake_var_fragment),
+    implementation = _cmake_file_list_impl,
     attrs = dict(
         _source_list_common_attrs,
         _header = attr.string(
@@ -416,6 +416,9 @@ def _automake_var_fragment(owner, varname, prefix, entries):
     )
     return fragment.rstrip("\\ ") + "\n"
 
+def _automake_file_list_impl(ctx):
+    _create_file_list_impl(ctx, _automake_var_fragment)
+
 gen_automake_file_lists = rule(
     doc = """
 Generates an Automake-syntax file with lists of files.
@@ -434,7 +437,7 @@ For proto_library, the following are generated:
     {libname}_hdrs: contains syntesized paths for generated C++ headers.
 
 """,
-    implementation = _create_file_list_impl(_automake_var_fragment),
+    implementation = _automake_file_list_impl,
     attrs = dict(
         _source_list_common_attrs.items(),
         _header = attr.string(