[clang] [Clang][Cygwin] don't use -Bsymbolic-functions (PR #138217)

[via cfe-commits]

https://github.com/jeremyd2019 created https://github.com/llvm/llvm-project/pull/138217

GNU ld seems to ignore this option, but LLD treats the presence of this unknown option as an error.

>From bc019f85e4e8d2e1e65879d1f8adaf92e2581a01 Mon Sep 17 00:00:00 2001
From: Jeremy Drake <github at jdrake.com>
Date: Sun, 13 Apr 2025 22:38:38 -0700
Subject: [PATCH] [Clang][Cygwin] don't use -Bsymbolic-functions

GNU ld seems to ignore this option, but LLD treats the presence of this
unknown option as an error.
---
 clang/tools/clang-shlib/CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clang/tools/clang-shlib/CMakeLists.txt b/clang/tools/clang-shlib/CMakeLists.txt
index 31484ec49c773..317964de4fb17 100644
--- a/clang/tools/clang-shlib/CMakeLists.txt
+++ b/clang/tools/clang-shlib/CMakeLists.txt
@@ -57,7 +57,7 @@ endif()
 
 # Optimize function calls for default visibility definitions to avoid PLT and
 # reduce dynamic relocations.
-if (NOT APPLE AND NOT MINGW AND NOT LLVM_LINKER_IS_SOLARISLD_ILLUMOS)
+if (NOT APPLE AND NOT MINGW AND NOT CYGWIN AND NOT LLVM_LINKER_IS_SOLARISLD_ILLUMOS)
   target_link_options(clang-cpp PRIVATE LINKER:-Bsymbolic-functions)
 endif()
 if (MINGW OR CYGWIN)