fixed bug in LOAD_BROADCAST_MASK_Half_VectorD method

git-svn-id: svn://svn.code.sf.net/p/bochs/code/trunk@12183 6c8e4198-a580-4521-a02f-c9ae86df1db9
implemented access to opmask AVX-512 registers from debugger, fixed enhdbg buffer overflow with EVEX enabled

git-svn-id: svn://svn.code.sf.net/p/bochs/code/trunk@12184 6c8e4198-a580-4521-a02f-c9ae86df1db9