[llvm] [DebugInfo] Fix Fortran 2018 default array lower bound (PR #210885)

[via llvm-commits]

https://github.com/firmiana402 created https://github.com/llvm/llvm-project/pull/210885

The [DWARF language registry](https://dwarfstd.org/languages.html) defines the default array lower bound for `DW_LANG_Fortran18` as one, but LLVM records it as zero. Update the language table to match the registry.


>From 25f3c49bac8f8e904acdb0acae3f397e93152af1 Mon Sep 17 00:00:00 2001
From: firmiana402 <firmiana402 at gmail.com>
Date: Tue, 21 Jul 2026 12:10:49 +0800
Subject: [PATCH] [DebugInfo] Fix Fortran 2018 default array lower bound

---
 llvm/include/llvm/BinaryFormat/Dwarf.def | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/include/llvm/BinaryFormat/Dwarf.def b/llvm/include/llvm/BinaryFormat/Dwarf.def
index 8bb1766bcc259..f301dbfba173f 100644
--- a/llvm/include/llvm/BinaryFormat/Dwarf.def
+++ b/llvm/include/llvm/BinaryFormat/Dwarf.def
@@ -1012,7 +1012,7 @@ HANDLE_DW_LANG(0x0028, Crystal, 0, 0, DWARF)
 HANDLE_DW_LANG(0x002a, C_plus_plus_17, 0, 0, DWARF)
 HANDLE_DW_LANG(0x002b, C_plus_plus_20, 0, 0, DWARF)
 HANDLE_DW_LANG(0x002c, C17, 0, 0, DWARF)
-HANDLE_DW_LANG(0x002d, Fortran18, 0, 0, DWARF)
+HANDLE_DW_LANG(0x002d, Fortran18, 1, 0, DWARF)
 HANDLE_DW_LANG(0x002e, Ada2005, 0, 0, DWARF)
 HANDLE_DW_LANG(0x002f, Ada2012, 0, 0, DWARF)
 HANDLE_DW_LANG(0x0030, HIP, 0, 0, DWARF)