[CUDA] Update docs to indicate that MacOS is now supported.

llvm-svn: 287290
GitOrigin-RevId: 2d2292009ff6715e1432a29e28d1303a1e36dacc
diff --git a/docs/CompileCudaWithLLVM.rst b/docs/CompileCudaWithLLVM.rst
index 585a5e7..8b29624 100644
--- a/docs/CompileCudaWithLLVM.rst
+++ b/docs/CompileCudaWithLLVM.rst
@@ -35,6 +35,9 @@
 
 You will need CUDA 7.0, 7.5, or 8.0 to compile with clang.
 
+CUDA compilation is supported on Linux, and on MacOS as of XXXX-XX-XX.  Windows
+support is planned but not yet in place.
+
 Invoking clang
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