format lengths and digits are sometimes not read correctly

[belegdol]

Hello,

while working on #361 I have noticed that format lengths and labels are sometimes not read at all - even for the formats not needing the PR. First investigation seems to indicate that it might have something to do with data representation: SOLARIS_X86_64, LINUX_X86_64, ALPHA_TRU64, LINUX_IA64 works fine but WINDOWS_64 does not.

[belegdol]

This happens because format_width and format_digits are only read for files for which ctx->u64 is true, but for WINDOWS_64 files it is 0.