Reduce the header to only bswap.h and cpu_ldst.h.
Move exec/translate-all.h to translator.c.
Reduce tcg.h and tcg-op.h to tcg-op-common.h.
Remove otherwise unused headers.

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