Improved the SCO Xenix fix, fixes OS/2 booting, fixes #4762.

src/mem/mem.c

@@ -225,6 +225,19 @@ flushmmucache(void)
 #endif
 }
 
+void
+flushmmucache_pc(void)
+{
+    mmuflush++;
+
+    pccache  = (uint32_t) 0xffffffff;
+    pccache2 = (uint8_t *) 0xffffffff;
+
+#ifdef USE_DYNAREC
+    codegen_flush();
+#endif
+}
+
 void
 flushmmucache_nopc(void)
 {