tcg: Respect highwater in tcg_out_tb_finalize

Undo the workaround at b17a6d3390f87620735f7efb03bb1c96682ff449.

If there are lots of memory operations in a TB, the slow path code
can exceed the highwater reservation.  Add a check within the loop.

Tested-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
diff --git a/tcg/tcg-be-null.h b/tcg/tcg-be-null.h
index 74c57d5..5222fe2 100644
--- a/tcg/tcg-be-null.h
+++ b/tcg/tcg-be-null.h
@@ -38,6 +38,7 @@
  * Generate TB finalization at the end of block
  */
 
-static inline void tcg_out_tb_finalize(TCGContext *s)
+static inline bool tcg_out_tb_finalize(TCGContext *s)
 {
+    return true;
 }