This intrinsic causes the compiler to behave as if all C objects had their values both read and written at that point in time.
To use this intrinsic, your source file must contain
#include <arm_compat.h>. This is only available
for targets in AArch32 state.
The compiler ensures that the stored value of each C object is correct at that point in time and treats the stored value as unknown afterwards.
This intrinsic also acts as a