target/i386: set CC_OP in helpers if they want CC_OP_EFLAGS

target/i386: set CC_OP in helpers if they want CC_OP_EFLAGS

Mark cc_op as clean and do not spill it at the end of the translation block.
Technically this is a tiny bit less efficient, but:

* it results in translations that are a tiny bit smaller

* for most of these instructions, it is not unlikely that they are close to
the end of the basic block, in which case cc_op would not be overwritten

* anyway the cost is probably dwarfed by that of computing flags.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>