For llvm-objdump and Mach-O files, update the printing of some thread states

from core files.  I tested this against the couple of core files that were
getting errors about unknown thread flavors and it now produce the same output as
the Xcode otool-classic(1) tool.  Since the core files are huge I didn’t include
them as test cases.

rdar://38216356

llvm-svn: 327077