PE DllCharacteristics field

[Myria]

I noticed that binutils doesn't support the DllCharacteristics field of PE 
files, always putting 0 there.  How might support for it be added in a 
future binutils?

The flags that would go there are "NX-compatible", "Terminal Services-aware" 
and "ASLR-compatible".

ASLR-compatible should require that relocation data be emitted, either DLL 
or -pie.  NX-compatible could validate that the entry point is in an 
executable section.