Add a --sysroot-extra-archives flag for jenkins-cheri-build

pycheribuild/config/jenkinsconfig.py

@@ -133,6 +133,10 @@ def __init__(self, loader: ConfigLoaderBase, available_targets: "list[str]") ->
             ),
             help="The path where to extract the sysroot (default=",
         )
+        self.sysroot_extra_archive_names = loader.add_commandline_only_list_option(
+            "sysroot-extra-archives",
+            help="Addition archives to extract within the sysroot",
+        )
         self.keep_install_dir = loader.add_commandline_only_bool_option(
             "keep-install-dir", help="Don't delete the install dir prior to build"
         )

pycheribuild/jenkins.py

@@ -168,6 +168,17 @@ def get_sdk_archives(cheri_config, needs_cheribsd_sysroot: bool) -> "list[SdkArc
         if contents.stdout.startswith(b"./"):
             warning_message("Old sysroot archive detected, stripping one more path component")
             sysroot_archive.extra_args = ["--strip-components", "2"]
+    for extra_name in cheri_config.sysroot_extra_archive_names:
+        extra_path = Path(extra_name)
+        extra_archive = SdkArchive(
+            cheri_config,
+            extra_path,
+            output_dir=cheri_config.sysroot_archive_output_path,
+        )
+        if not extra_archive.archive.exists():
+            fatal_error("Extra archive", extra_archive.archive, "does not exist", pretend=cheri_config.pretend)
+        else:
+            all_archives.append(extra_archive)
     return all_archives