Hash function construction
The construction is trivially neither collision resistant nor second preimage resistant, since XOR is commutative. I.e. for any $a,b$ it holds that $a\oplus b = b \oplus a$.
Consequently, given $M_1,M_2$ as a first preimage, we can trivially find $M_2,M_1$ as a second preimage. To break collision resistance, simply choose $M_1,M_2$ arbitrarily.