binutils: detect the "gold" and "headers" variants (#40214)

Co-authored-by: Massimiliano Culpo <massimiliano.culpo@gmail.com>

var/spack/repos/builtin/packages/binutils/package.py

@@ -3,6 +3,7 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 import os
+import pathlib
 import re
 
 import spack.build_systems.autotools
@@ -177,6 +178,20 @@ def determine_version(cls, exe):
         match = re.search(r"GNU (nm|readelf).* (\S+)", output)
         return Version(match.group(2)).dotted.up_to(3) if match else None
 
+    @classmethod
+    def determine_variants(cls, exes, version_str):
+        bin_dir = pathlib.Path(exes[0]).parent
+        include_dir = bin_dir.parent / "include"
+        plugin_h = include_dir / "plugin-api.h"
+
+        variants = "+gold" if find(str(bin_dir), "gold", recursive=False) else "~gold"
+        if find(str(include_dir), str(plugin_h), recursive=False):
+            variants += "+headers"
+        else:
+            variants += "~headers"
+
+        return variants
+
     def flag_handler(self, name, flags):
         spec = self.spec