Loadable modules are not supported on Cygwin. PR 6655.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117130 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/cmake/modules/AddLLVM.cmake b/cmake/modules/AddLLVM.cmake
index b7ebe19..f45febb 100755
--- a/cmake/modules/AddLLVM.cmake
+++ b/cmake/modules/AddLLVM.cmake
@@ -29,7 +29,7 @@
 
 
 macro(add_llvm_loadable_module name)
-  if( NOT LLVM_ON_UNIX )
+  if( NOT LLVM_ON_UNIX OR CYGWIN )
     message(STATUS "Loadable modules not supported on this platform.
 ${name} ignored.")
   else()