libstdc++: use extern "C++" in all our C++ system headers.
This is needed to build an independent toolchain with g++ that doesn't think
that all these headers are in C.
Change-Id: Ie9a8ccfcab7780d6a4e5722777d61c2b1b312001
diff --git a/libstdc++/include/cstdio b/libstdc++/include/cstdio
index d46a18b..3c8b5c6 100644
--- a/libstdc++/include/cstdio
+++ b/libstdc++/include/cstdio
@@ -36,6 +36,8 @@
#include <cstddef>
#include <stdio.h>
+extern "C++" {
+
namespace std {
using ::FILE;
using ::fpos_t;
@@ -89,4 +91,6 @@
using ::vsscanf;
} // namespace std
+} // extern C++
+
#endif // BIONIC_LIBSTDCPP_INCLUDE_CSTDIO__