[llvm] [MC] Explicitly mark MCSymbol for MO_ExternalSymbol (PR #108880)

[weiwei chen via llvm-commits]

https://github.com/weiweichen created https://github.com/llvm/llvm-project/pull/108880

- [x] Mark `MCSymbol` for `MO_ExternalSymbol` to be external when created. 

>From 8bf3c85978b774c0606e5d1be7cbd3415f036259 Mon Sep 17 00:00:00 2001
From: Weiwei Chen <weiwei.chen at modular.com>
Date: Mon, 16 Sep 2024 20:37:30 +0000
Subject: [PATCH] Explicitly mark MCSymbol for MO_ExternalSymbol

---
 llvm/lib/Target/X86/X86MCInstLower.cpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/llvm/lib/Target/X86/X86MCInstLower.cpp b/llvm/lib/Target/X86/X86MCInstLower.cpp
index 77ddd2366e629e..949711f35aa584 100644
--- a/llvm/lib/Target/X86/X86MCInstLower.cpp
+++ b/llvm/lib/Target/X86/X86MCInstLower.cpp
@@ -350,8 +350,11 @@ MCOperand X86MCInstLower::LowerMachineOperand(const MachineInstr *MI,
     return MCOperand::createImm(MO.getImm());
   case MachineOperand::MO_MachineBasicBlock:
   case MachineOperand::MO_GlobalAddress:
-  case MachineOperand::MO_ExternalSymbol:
-    return LowerSymbolOperand(MO, GetSymbolFromOperand(MO));
+  case MachineOperand::MO_ExternalSymbol: {
+    MCSymbol *Sym = GetSymbolFromOperand(MO);
+    Sym->setExternal(true);
+    return LowerSymbolOperand(MO, Sym);
+  }
   case MachineOperand::MO_MCSymbol:
     return LowerSymbolOperand(MO, MO.getMCSymbol());
   case MachineOperand::MO_JumpTableIndex: