[C] Add _Static_assert definition when compiling with MSVC.

Author: vyazelenko

aeron-client/src/main/c/protocol/aeron_udp_protocol.c

@@ -19,6 +19,10 @@
 #include "util/aeron_bitutil.h"
 #include "aeron_udp_protocol.h"
 
+#ifdef _MSC_VER
+#define _Static_assert static_assert
+#endif
+
 _Static_assert(
     sizeof(aeron_data_header_as_longs_t) == sizeof(aeron_data_header_t),
     "sizeof(aeron_data_header_as_longs_t) must match sizeof(aeron_data_header_t)");