The thread swap test was making use of a register to point to
ztest_thread_callee_saved_regs_container, which was being clobbered
in the inline assembly code, causing a hard-fault in certain cases.
This commit adds a clobber list of the registers used, causing the
compiler to assign ztest_thread_callee_saved_regs_container to an
appropriate (unclobbered) register.
It also addresses an issue in the v6-m and v8-m.baseline inline
assembler where only 4 of the 8 callee-saved registers were being
set from ztest_thread_callee_saved_regs_container, due to a double
use of `ldmia` on the same four registers. Since v6-m devices can't
operate outside r0-r7 on most instructions, the upper 4 callee-saved
registers are set first with `ldmia`, before setting the lower 4.
Signed-off-by: Kevin Townsend <kevin.townsend@linaro.org>
07de2ffbb0