#582 Consider implementing strtab suffix merging in libelftc

[Ed Maste]

In [r3757] elfcopy started using libelftc's string table routines to build .shstrtab, as it's much faster. However, this removed suffix merge (e.g. .rela.text and .text sharing string table storage). Consider implementing suffix merging in libelftc's routines to restore this (across all consumers).

(Perhaps consider also merging .shstrtab and .strtab under certain conditions later on; this might be a big benefit with -ffunction-sections, and I believe llvm does this.)

See ticket [#575] and [r3828] for more details.

[Ed Maste]

As mark points out the benefit from merging within .shstrtab is likely small, generally a handful of .rel or .rela sections. The real benefit would come from merging .shstrtab and .strtab but there are a limited number of cases where it's possible to do so.