Update default disassembly format string so we get

better output when we don't have any symbol name.
It looked like this:

0x1097fd029 <ud2    
0x1097fd02b <addb   %al, (%rax)

now, like this:

0x10cdd3064: ud2    
0x10cdd3066: addb   %al, (%rax)

<rdar://problem/18833391> 

llvm-svn: 220948