This reverts commit 52f0c1607671293afcdb2acc2f83e9bccbfa74bb.
This caused a regression in arm/aarch64.
We are hard-coding ARMCPRegInfo pointers into TranslationBlocks,
for calling into helper_{get,set}cp_reg{,64}. So we have a race
condition between whichever cpu thread translates the code first
(encoding the pointer), and that cpu thread exiting, so that the
next execution of the TB references a freed data structure.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>