Handle 64-bit binaries in elf/dl

[NiLuJe]

That should hopefully have been the last non-toolchain-related hurdle for an aarch64 build ;).

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This change is 

[Frenzie]

If you say so. :-P

[pazos]

That should hopefully have been the last non-toolchain-related hurdle for an aarch64 build ;).

The standalone example worked before, but I guess it was because LuaJIT was part of the main shared lib?

[NiLuJe]

@pazos: What standalone example? ^^.

(The two formats are very similar, there's a vague chance using the Elf32 data types on a 64-bit host mostly worked for what we were doing).

[Frenzie]

@NiLuJe examples/helloWorld I imagine

[NiLuJe]

Yep, confirmed that it failed on Elf64 files before (random test on an x64 binary ;p).

luajit utils/print_dt_needed.lua /usr/bin/ag

luajit: utils/elf.lua:164: no .dynstr section in /usr/bin/ag
stack traceback:
        [C]: in function 'assert'
        utils/elf.lua:164: in function 'dlneeds'
        utils/print_dt_needed.lua:14: in main chunk
        [C]: at 0x55d8662fdfc0

needed => libpcre.so.1 (1 of 5) <= /usr/bin/ag
needed => liblzma.so.5 (2 of 5) <= /usr/bin/ag
needed => libz.so.1 (3 of 5) <= /usr/bin/ag
needed => libpthread.so.0 (4 of 5) <= /usr/bin/ag
needed => libc.so.6 (5 of 5) <= /usr/bin/ag

[NiLuJe]

Tweaked the logging and asserts some more, and actually tested on a real device ;p.