Implement the debug save restore as a direct translation of
the assembly code version.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Tested-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>