windows meson: OVS_PREFETCH and __GNUC__ not defined

[williamtu]

In file included from ../ovsdb/row.c:28: ..\lib/util.h:81:17: warning: unused variable 'addr' [-Wunused-variable] const char addr = (const char )start; ^ 1 warning generated.

[williamtu]

not sure if we should define GNUC or just defined clang

--- a/include/openvswitch/compiler.h +++ b/include/openvswitch/compiler.h @@ -230,7 +230,7 @@

• written to. Depending on the target CPU, this can generate the same
• instruction as OVS_PREFETCH(), or bring the data into the cache in an
• exclusive state. */ -#if GNUC +#if GNUC || clang

  define OVS_PREFETCH(addr) __builtin_prefetch((addr))

  define OVS_PREFETCH_WRITE(addr) __builtin_prefetch((addr), 1)

  else