[CMake] Enable loadable modules, aka plugins, with BUILD_SHARED_LIBS …

…on cygming.

Loadable modules could be enabled without BUILD_SHARED_LIBS with tweaks in future.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212907 91177308-0d34-0410-b5e6-96231b3b80d8

cmake/modules/HandleLLVMOptions.cmake

@@ -411,8 +411,11 @@ endif()
 # Plugin support
 # FIXME: Make this configurable.
 if(WIN32 OR CYGWIN)
-  # DLL platform(s) don't support plugins.
-  set(LLVM_ENABLE_PLUGINS OFF)
+  if(BUILD_SHARED_LIBS)
+    set(LLVM_ENABLE_PLUGINS ON)
+  else()
+    set(LLVM_ENABLE_PLUGINS OFF)
+  endif()
 else()
   set(LLVM_ENABLE_PLUGINS ON)
 endif()