[llvm] [LLMV] set OpenBSD's ELFOSABI by default (PR #98158)

[John Ericson via llvm-commits]

https://github.com/Ericson2314 created https://github.com/llvm/llvm-project/pull/98158

This matches what is done for FreeBSD.

OpenBSD has a few special program header types, and other such ELF extensions. Setting the ELFOSABI like so will allow LLD to support them without needlessly impacting non-OpenBSD ELFs.

>From bd7871b501c14be71e8671770918bdd82c78ab8d Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson at Obsidian.Systems>
Date: Sun, 30 Jun 2024 18:47:58 -0400
Subject: [PATCH] [LLMV] set OpenBSD's ELFOSABI by default

This matches what is done for FreeBSD.

OpenBSD has a few special program header types, and other such ELF
extensions. Setting the ELFOSABI like so will allow LLD to support them
without needlessly impacting non-OpenBSD ELFs.
---
 llvm/include/llvm/MC/MCELFObjectWriter.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/llvm/include/llvm/MC/MCELFObjectWriter.h b/llvm/include/llvm/MC/MCELFObjectWriter.h
index d7c223cdcc07f..12237094ad86a 100644
--- a/llvm/include/llvm/MC/MCELFObjectWriter.h
+++ b/llvm/include/llvm/MC/MCELFObjectWriter.h
@@ -78,6 +78,8 @@ class MCELFObjectTargetWriter : public MCObjectTargetWriter {
         return ELF::ELFOSABI_FREEBSD;
       case Triple::Solaris:
         return ELF::ELFOSABI_SOLARIS;
+      case Triple::OpenBSD:
+        return ELF::ELFOSABI_OPENBSD;
       default:
         return ELF::ELFOSABI_NONE;
     }