tcg: Add tlb_fast_offset to TCGContext

Disconnect the layout of ArchCPU from TCG compilation.
Pass the relative offset of 'env' and 'neg.tlb.f' as a parameter.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

include/tcg/tcg.h

@@ -547,6 +547,7 @@ struct TCGContext {
     TCGType addr_type;            /* TCG_TYPE_I32 or TCG_TYPE_I64 */
 
 #ifdef CONFIG_SOFTMMU
+    int tlb_fast_offset;
     int page_mask;
     uint8_t page_bits;
     uint8_t tlb_dyn_max_bits;