Dynarec: Force interpreter on pages that undergo excessive invalidation, improves % on TES Daggerfall and potentially other self-modifying code

src/include/86box/86box.h

@@ -320,6 +320,7 @@ extern void do_pause(int p);
 extern double isa_timing;
 extern int    io_delay;
 extern int    framecountx;
+extern int    seconds_elapsed;
 
 extern volatile int     cpu_thread_run;
 extern          uint8_t postcard_codes[POSTCARDS_NUM];

src/include/86box/mem.h

@@ -224,6 +224,9 @@ typedef struct page_t {
 
     uint64_t *byte_dirty_mask;
     uint64_t *byte_code_present_mask;
+
+    uint32_t inv_count;
+    uint32_t inv_timestamp;
 } page_t;
 
 extern uint32_t purgable_page_list_head;
@@ -250,6 +253,9 @@ typedef struct _page_ {
 
     /*Head of codeblock tree associated with this page*/
     struct codeblock_t *head;
+
+    uint32_t inv_count;
+    uint32_t inv_timestamp;
 } page_t;
 #endif