Fix many -Wunused-parameter

Remove unused InnoDB function parameters and functions.

i_s_sys_virtual_fill_table(): Do not allocate heap memory.

mtr_is_block_fix(): Replace with mtr_memo_contains().

mtr_is_page_fix(): Replace with mtr_memo_contains_page().

sql/sql_string.h

@@ -190,7 +190,7 @@ public:
   { /* never called */ }
   static void operator delete[](void *ptr, size_t size)
   { TRASH_FREE(ptr, size); }
-  static void operator delete[](void *ptr, MEM_ROOT *mem_root)
+  static void operator delete[](void *, MEM_ROOT *)
   { /* never called */ }
 
   ~String() { free(); }