Move `crubit_feature_hint.bzl` to `crubit/features`.

This is going to be used by both rs_bindings_from_cc and cc_bindings_from_rs, so it needs to go into a common directory. There's two pretty obvious options:

* crubit/common/bazel_support
* crubit/features

I think the second one is more "self-contained" and puts code closer together and less spread out throughout the codebase, so I put it there.

PiperOrigin-RevId: 663652310
Change-Id: Ib16a7453cd8435166d51cb40580abfa9af6e4c56
diff --git a/features/BUILD b/features/BUILD
index 411176a..0381859 100644
--- a/features/BUILD
+++ b/features/BUILD
@@ -1,5 +1,6 @@
+load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
 load(
-    "//rs_bindings_from_cc/bazel_support:crubit_feature_hint.bzl",
+    ":crubit_feature_hint.bzl",
     "crubit_feature_hint",
 )
 
@@ -43,3 +44,13 @@
     crubit_features = ["experimental"],
     visibility = ["//:__subpackages__"],
 )
+
+# Implementation details follow.
+
+bzl_library(
+    name = "crubit_feature_hint_bzl",
+    srcs = ["crubit_feature_hint.bzl"],
+    visibility = [
+        "//:__subpackages__",
+    ],
+)
diff --git a/rs_bindings_from_cc/bazel_support/crubit_feature_hint.bzl b/features/crubit_feature_hint.bzl
similarity index 100%
rename from rs_bindings_from_cc/bazel_support/crubit_feature_hint.bzl
rename to features/crubit_feature_hint.bzl
diff --git a/rs_bindings_from_cc/bazel_support/BUILD b/rs_bindings_from_cc/bazel_support/BUILD
index bfa8300..c1c30ce 100644
--- a/rs_bindings_from_cc/bazel_support/BUILD
+++ b/rs_bindings_from_cc/bazel_support/BUILD
@@ -19,10 +19,10 @@
     ],
     deps = [
         ":additional_rust_srcs_for_crubit_bindings_aspect_hint_bzl",
-        ":crubit_feature_hint_bzl",
         ":providers_bzl",
         ":rust_bindings_from_cc_cli_flag_aspect_hint",
         ":rust_bindings_from_cc_utils_bzl",
+        "//features:crubit_feature_hint_bzl",
     ],
 )
 
@@ -95,11 +95,6 @@
 )
 
 bzl_library(
-    name = "crubit_feature_hint_bzl",
-    srcs = ["crubit_feature_hint.bzl"],
-)
-
-bzl_library(
     name = "generate_bindings_bzl",
     srcs = ["generate_bindings.bzl"],
     deps = ["@bazel_tools//tools/build_defs/cc:action_names"],
diff --git a/rs_bindings_from_cc/bazel_support/rust_bindings_from_cc_aspect.bzl b/rs_bindings_from_cc/bazel_support/rust_bindings_from_cc_aspect.bzl
index 928da56..d06eb22 100644
--- a/rs_bindings_from_cc/bazel_support/rust_bindings_from_cc_aspect.bzl
+++ b/rs_bindings_from_cc/bazel_support/rust_bindings_from_cc_aspect.bzl
@@ -8,12 +8,12 @@
 """
 
 load(
-    "@@//rs_bindings_from_cc/bazel_support:additional_rust_srcs_for_crubit_bindings_aspect_hint.bzl",
-    "get_additional_rust_srcs",
+    "//features:crubit_feature_hint.bzl",
+    "find_crubit_features",
 )
 load(
-    "@@//rs_bindings_from_cc/bazel_support:crubit_feature_hint.bzl",
-    "find_crubit_features",
+    "@@//rs_bindings_from_cc/bazel_support:additional_rust_srcs_for_crubit_bindings_aspect_hint.bzl",
+    "get_additional_rust_srcs",
 )
 load(
     "@@//rs_bindings_from_cc/bazel_support:providers.bzl",