[DWARF] Add CIE header fields address_size and segment_size when generating dwarf-4

The DWARF-4 specification added 2 new fields in the CIE header called
address_size and segment_size.
Create these 2 new fields when generating dwarf-4 CIE entries, print out
the new fields when dumping the CIE and update tests

Differential Revision: http://reviews.llvm.org/D9558

llvm-svn: 237145