[RFAv2 0/4] Fix some gdb.ada tests failure by using more unique names.

[Philippe Waroquiers]

This patch serie fixes some gdb.ada tests failure that appear when
the Ada runtime is compiled with debug info, e.g. like the Debian
gcc Ada compiler.

The changes compared to first version of RFA are:
* Each test is fixed in a different commit.
* The component order in packed_array_assign Packed_Rec is chosen to
  ensure old and new compilers produce the same component order.

Ok to push ?