[lld] [LLD] [MinGW] Implement --dependent-load-flag option (PR #113814)

[Martin Storsjö via llvm-commits]

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@@ -61,6 +61,7 @@ defm demangle: B<"demangle",
     "Do not demangle symbol names">;
 def disable_auto_import: F<"disable-auto-import">,
     HelpText<"Don't automatically import data symbols from other DLLs without dllimport">;
+defm dependent_load_flag: EEq<"dependent-load-flag", "Override default LibraryLoad flags">;
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mstorsjo wrote:

I'd say we should go with `EEq` for new stuff, i.e. only allow the form `--dependent-load-flag`, not `-dependent-load-flag`.

I think the reason is that getopt which binutils use, is pretty relaxed and allows either `--` or `-` as long as things aren't ambiguous, so for such cases if binutils happens to accept both forms (and especially if both forms are in use in the wild), we need to accept both forms. But for new options that we make up ourselves I don't see any reason to accept anything else than the proper double-dash form.

https://github.com/llvm/llvm-project/pull/113814