fix blocking bugs in command nr_dlsim -n100 -e27 -s35 -b 273 -R273 -x4 -y4 -z4

errors in main OAI code:

- one stack overflow
- one variable array of size 0
- one direct usage of unaligned SIMD

and small fixes inside the tests tool nr_dlsim to handle this large configuration (4layers, 100MHz)

use a better complex vector multiplication function