include/exec: Remove CODE_GEN_AVG_BLOCK_SIZE

The last use was removed with 2ac01d6d.

Fixes: 2ac01d6d ("translate-all: use a binary search tree to track TBs in TBContext")
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

include/exec/exec-all.h

@@ -467,16 +467,6 @@ int probe_access_full(CPUArchState *env, target_ulong addr, int size,
                       CPUTLBEntryFull **pfull, uintptr_t retaddr);
 #endif
 
-/* Estimated block size for TB allocation.  */
-/* ??? The following is based on a 2015 survey of x86_64 host output.
-   Better would seem to be some sort of dynamically sized TB array,
-   adapting to the block sizes actually being produced.  */
-#if defined(CONFIG_SOFTMMU)
-#define CODE_GEN_AVG_BLOCK_SIZE 400
-#else
-#define CODE_GEN_AVG_BLOCK_SIZE 150
-#endif
-
 /* Hide the qatomic_read to make code a little easier on the eyes */
 static inline uint32_t tb_cflags(const TranslationBlock *tb)
 {