implement avx-512 vpabsd/q instructions

git-svn-id: svn://svn.code.sf.net/p/bochs/code/trunk@11980 6c8e4198-a580-4521-a02f-c9ae86df1db9
Fixed 8-bit opmask read
Added opmask printout for AVX dump in dbg_main.cc 


git-svn-id: svn://svn.code.sf.net/p/bochs/code/trunk@11981 6c8e4198-a580-4521-a02f-c9ae86df1db9