[RFA 00/22] More C++-ification

[Tom Tromey <tom at tromey dot com>]

This patch series converts more random parts of gdb to C++.

Some of these patches get rid of cleanups, or convert them to RAII.
In a couple of cases, after removing cleanups I went further and
converted a given class more fully to C++.  There's also one random
patch to convert an iterator to a C++ class using RAII.

I didn't touch any spot where the cleanup removal would have benefited
from unique_ptr; Pedro has a branch with the needed bits there, and I
wanted to avoid conflicts with his work.

This was built and regtested on x86-64 Fedora 24.

I've appended the differences between the baseline run and the run
with this series in place.  I don't know whether these represent real
regressions or are just intermittent test failures; particularly
because the missing tests are either FAIL or KFAIL.

Tom

Missing tests:
gdb.threads/process-dies-while-handling-bp.exp: non_stop=off: cond_bp_target=0: inferior 1 exited (memory error): KFAIL
gdb.threads/process-dies-while-handling-bp.exp: non_stop=off: cond_bp_target=1: inferior 1 exited (prompt): KFAIL
gdb.threads/process-dies-while-handling-bp.exp: non_stop=on: cond_bp_target=0: inferior 1 exited (prompt): KFAIL
gdb.threads/watchpoint-fork.exp: child: multithreaded: breakpoint (A) after the second fork: FAIL

New tests:
gdb.threads/process-dies-while-handling-bp.exp: non_stop=off: cond_bp_target=1: inferior 1 exited (memory error): KFAIL
gdb.threads/process-dies-while-handling-bp.exp: non_stop=on: cond_bp_target=0: inferior 1 exited (memory error): KFAIL