Add missing initializations of the SenderMachine field of out_msg's when thery are created in the L2 cache controller of the MOESI_CMP_directory coherence protocol. When an out_msg is created and this field is left uninitialized, it is set to the default value MachineType_NUM. This causes a panic in the MachineType_to_string function when gem5 is executed with the Ruby debug flag on and it tries to print the message.

Simple OpenMP vector addition microbenchmark running with the following command:

./build/X86/gem5.debug --debug-flags=Ruby --redirect-stdout --redirect-stderr configs/example/se.py --output=/tmp/bench.out --errout=/tmp/bench.err --ruby --cpu-type=detailed --num-cpus=4 --num-l2caches=4 --l2_size=1MB --num-dirs=4 --topology=Mesh -c /home/lluc/NAS/bin/vecadd -o "-numthreads 4"