Use deposit32() rather than handcoded shifts/masks to update the scratch registers. This is cleaner and incidentally avoids a clang sanitizer complaint ("runtime error: left shift of 255 by 24 places cannot be represented in type 'int'"). Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>