Fix clang build failure

src/network/net_ne2000.c

@@ -68,6 +68,7 @@
 #include <86box/net_ne2000.h>
 #include <86box/bswap.h>
 #include <86box/isapnp.h>
+#include <86box/plat_fallthrough.h>
 #include <86box/plat_unused.h>
 
 /* ROM BIOS file paths. */
@@ -749,7 +750,7 @@ nic_pci_write(UNUSED(int func), int addr, uint8_t val, void *priv)
         case 0x10:       /* PCI_BAR */
             val &= 0xe0; /* 0xe0 acc to RTL DS */
             val |= 0x01; /* re-enable IOIN bit */
-#ifndef __APPLE__
+#ifdef FALLTHROUGH_ANNOTATION
             [[fallthrough]];
 #endif
 

src/network/net_wd8003.c

@@ -64,6 +64,7 @@
 #include <86box/net_dp8390.h>
 #include <86box/net_wd8003.h>
 #include <86box/bswap.h>
+#include <86box/plat_fallthrough.h>
 #include <86box/plat_unused.h>
 
 #include "cpu.h"
@@ -734,7 +735,7 @@ wd_init(const device_t *info)
         /* Ethernet, MCA, 5x3 interface chip, RAM 16k */
         case WD8003EA:
             dev->board_chip = WE_ID_SOFT_CONFIG;
-#ifndef __APPLE__
+#ifdef FALLTHROUGH_ANNOTATION
             [[fallthrough]];
 #endif
         /* Ethernet, MCA, no interface chip, RAM 16k */