[lld] [LLD][COFF] Use primary symbol table machine in Writer::writeHeader (NFC) (PR #128442)

[Jacek Caban via llvm-commits]

https://github.com/cjacek created https://github.com/llvm/llvm-project/pull/128442

Instead of duplicating the logic from `LinkerDriver::setMachine`.

>From 02fb7bbf281b9329060b4c95993d49c878c93593 Mon Sep 17 00:00:00 2001
From: Jacek Caban <jacek at codeweavers.com>
Date: Sun, 23 Feb 2025 23:36:23 +0100
Subject: [PATCH] [LLD][COFF] Use primary symbol table machine in
 Writer::writeHeader (NFC)

Instead of duplicating the logic from LinkerDriver::setMachine.
---
 lld/COFF/Writer.cpp | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/lld/COFF/Writer.cpp b/lld/COFF/Writer.cpp
index 58727c1615769..3efbcdb452ebe 100644
--- a/lld/COFF/Writer.cpp
+++ b/lld/COFF/Writer.cpp
@@ -1758,16 +1758,7 @@ template <typename PEHeaderTy> void Writer::writeHeader() {
   assert(coffHeaderOffset == buf - buffer->getBufferStart());
   auto *coff = reinterpret_cast<coff_file_header *>(buf);
   buf += sizeof(*coff);
-  switch (config->machine) {
-  case ARM64EC:
-    coff->Machine = AMD64;
-    break;
-  case ARM64X:
-    coff->Machine = ARM64;
-    break;
-  default:
-    coff->Machine = config->machine;
-  }
+  coff->Machine = ctx.symtab.isEC() ? AMD64 : ctx.symtab.machine;
   coff->NumberOfSections = ctx.outputSections.size();
   coff->Characteristics = IMAGE_FILE_EXECUTABLE_IMAGE;
   if (config->largeAddressAware)