[PATCH] Pack dwarf2_per_cu_data a bit better

[Tom Tromey]

>>>>> "Tom" == Tom Tromey <tom@tromey.com> writes:

Tom> This rearranges dwarf2_per_cu_data a little.  On x86-64 Fedora this
Tom> saves 16 bytes at, I believe, essentially no cost.

Tom> gdb/ChangeLog
Tom> 2021-03-31  Tom Tromey  <tom@tromey.com>

Tom> 	* dwarf2/read.h (struct dwarf2_per_cu_data): Pack.

I recently remembered that I did this once before, but a bit better:

https://sourceware.org/pipermail/gdb-patches/2020-November/173029.html

I'm going to check in that version instead.
I'll also re-examine Gary's reply to see if there are more changes that
make sense to make.

Tom