Make some static tables and strings constants.

Make some static tables and strings constants.

By doing this we move them from the .data section to .rodata setion,
or from .data.rel to .data.rel.ro.

The .rodata section is mapped directly from the on-disk file, which is
always a save, while .data.rel.ro is mapped directly when using
prelink, which is a save in a lot of cases.

Signed-off-by: Diego E. 'Flameeyes' Pettenò <flameeyes@gmail.com>