[PATCH v2 0/8] Handle copy relocations and add $_ada_exception

[Tom Tromey <tromey at adacore dot com>]

This is v2 of the patch series to add copy relocation support to gdb,
and to implement the $_ada_exception convenience variable.

v1 was here:

    https://sourceware.org/ml/gdb-patches/2019-08/msg00014.html

I believe this version addresses all the review comments.

I've merged some patches (in particular Pedro and Andrew both sent
test case improvements, and I squashed these) and reordered the series
a bit in an attempt to remove some intermediate regressions.
(However, a couple still remain, and I didn't want to go all-out and
squash most of the series.)

Let me know what you think.

Tom