separateDebugInfo: Create symlinks matching original binaries

For instance, a binary like libfoo.so will cause a symlink
lib/debug/libfoo.so.debug -> .build-id/<build-ID>.debug to be
created. This is primarily useful for use with eu-addr2line, if you
know the name of a binary and the relative address, but not the build
ID.

pkgs/build-support/setup-hooks/separate-debug-info.sh

@@ -32,6 +32,9 @@ _separateDebugInfo() {
         mkdir -p "$dst/${id:0:2}"
         objcopy --only-keep-debug "$i" "$dst/${id:0:2}/${id:2}.debug" --compress-debug-sections
         strip --strip-debug "$i"
+
+        # Also a create a symlink <original-name>.debug.
+        ln -sfn ".build-id/${id:0:2}/${id:2}.debug" "$dst/../$(basename "$i")"
     done
 }