Windows support by Ruben Van Boxem.

llvm-svn: 142235
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 073458b1ab5489dce6f2ec789889c377b690ccf4
diff --git a/include/complex.h b/include/complex.h
index e04b2e3..7003d31 100644
--- a/include/complex.h
+++ b/include/complex.h
@@ -28,6 +28,8 @@
 
 #endif  // __cplusplus
 
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
+#endif
 
 #endif  // _LIBCPP_COMPLEX_H