__declspec is not a core Clang language extension. Instead, require -fms-extensions or -fborland to enable the language extension.

Note: __declspec is also temporarily enabled when compiling for a CUDA target because there are implementation details relying on __declspec(property) support currently. When those details change, __declspec should be disabled for CUDA targets.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@238238 91177308-0d34-0410-b5e6-96231b3b80d8