Fixing r116753 r116756 r116777

The failures in r116753 r116756 were caused by a python issue -
Python likes to append 'L' suffix to stringified numbers if the number
is larger than a machine int. Unfortunately, this causes a divergence of
behavior between 32 and 64 bit python versions.

I re-crafted elf-dump/common_dump to take care of these issues by:

1. always printing 0x (makes for easy sed/regex)
2. always print fixed length (exactly 2 + numBits/4 digits long)
   by mod ((2^numBits) - 1)
3. left-padded with '0'

There is a residual common routine that is also used by
macho-dump (dataToHex) , so I left the 'section_data' test values alone.

llvm-svn: 116823