Support for alwayslink outputs.

Bazel uses a different extension for things that are marked as alwayslink, so
support that extension also.

PiperOrigin-RevId: 553798483
(cherry picked from commit c9768e0)
Signed-off-by: Brentley Jones <github@brentleyjones.com>

doc/rules.md

@@ -226,7 +226,7 @@ the `.private.swiftinterface` files are required in order to build any code that
 | <a id="swift_import-name"></a>name |  A unique name for this target.   | <a href="https://bazel.build/concepts/labels#target-names">Name</a> | required |  |
 | <a id="swift_import-deps"></a>deps |  A list of targets that are dependencies of the target being built, which will be linked into that target.<br><br>If the Swift toolchain supports implementation-only imports (`private_deps` on `swift_library`), then targets in `deps` are treated as regular (non-implementation-only) imports that are propagated both to their direct and indirect (transitive) dependents.<br><br>Allowed kinds of dependencies are:<br><br>*   `swift_library` (or anything propagating `SwiftInfo`)<br><br>*   `cc_library` (or anything propagating `CcInfo`)<br><br>Additionally, on platforms that support Objective-C interop, `objc_library` targets (or anything propagating the `apple_common.Objc` provider) are allowed as dependencies. On platforms that do not support Objective-C interop (such as Linux), those dependencies will be **ignored.**   | <a href="https://bazel.build/concepts/labels">List of labels</a> | optional |  `[]`  |
 | <a id="swift_import-data"></a>data |  The list of files needed by this target at runtime.<br><br>Files and targets named in the `data` attribute will appear in the `*.runfiles` area of this target, if it has one. This may include data files needed by a binary or library, or other programs needed by it.   | <a href="https://bazel.build/concepts/labels">List of labels</a> | optional |  `[]`  |
-| <a id="swift_import-archives"></a>archives |  The list of `.a` files provided to Swift targets that depend on this target.   | <a href="https://bazel.build/concepts/labels">List of labels</a> | optional |  `[]`  |
+| <a id="swift_import-archives"></a>archives |  The list of `.a` or `.lo` files provided to Swift targets that depend on this target.   | <a href="https://bazel.build/concepts/labels">List of labels</a> | optional |  `[]`  |
 | <a id="swift_import-module_name"></a>module_name |  The name of the module represented by this target.   | String | required |  |
 | <a id="swift_import-swiftdoc"></a>swiftdoc |  The `.swiftdoc` file provided to Swift targets that depend on this target.   | <a href="https://bazel.build/concepts/labels">Label</a> | optional |  `None`  |
 | <a id="swift_import-swiftinterface"></a>swiftinterface |  The `.swiftinterface` file that defines the module interface for this target. May not be specified if `swiftmodule` is specified.   | <a href="https://bazel.build/concepts/labels">Label</a> | optional |  `None`  |

swift/swift_import.bzl

@@ -155,9 +155,9 @@ swift_import = rule(
         {
             "archives": attr.label_list(
                 allow_empty = True,
-                allow_files = ["a"],
+                allow_files = ["a", "lo"],
                 doc = """\
-The list of `.a` files provided to Swift targets that depend on this target.
+The list of `.a` or `.lo` files provided to Swift targets that depend on this target.
 """,
                 mandatory = False,
             ),