[llvm] [Cygwin] CYGWIN is not WIN32 in current CMake (PR #143130)

[Tomohiro Kashiwada via llvm-commits]

https://github.com/kikairoya created https://github.com/llvm/llvm-project/pull/143130

On old CMake, Cygwin were also WIN32 but currently not. LLVM_ON_UNIX=1 and LLVM_HAVE_LINK_VERSION_SCRIPT=0 should be defined for Cygwin target.

>From 3cacbfcbdc53208812b582dfab29f78a59e2ec61 Mon Sep 17 00:00:00 2001
From: kikairoya <kikairoya at gmail.com>
Date: Mon, 28 Apr 2025 19:26:29 +0900
Subject: [PATCH] [Cygwin] CYGWIN is not WIN32 in current CMake

On old CMake, Cygwin were also WIN32 but currently not.
LLVM_ON_UNIX=1 and LLVM_HAVE_LINK_VERSION_SCRIPT=0 should
be defined for Cygwin target.
---
 llvm/cmake/modules/HandleLLVMOptions.cmake | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
index 9721dacbcbe84..866f5b8d9697a 100644
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -214,15 +214,15 @@ if( LLVM_REVERSE_ITERATION )
   set( LLVM_ENABLE_REVERSE_ITERATION 1 )
 endif()
 
-if(WIN32)
+if(WIN32 OR CYGWIN)
   set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
   if(CYGWIN)
     set(LLVM_ON_WIN32 0)
     set(LLVM_ON_UNIX 1)
-  else(CYGWIN)
+  else()
     set(LLVM_ON_WIN32 1)
     set(LLVM_ON_UNIX 0)
-  endif(CYGWIN)
+  endif()
 elseif(FUCHSIA OR UNIX)
   set(LLVM_ON_WIN32 0)
   set(LLVM_ON_UNIX 1)