[PATCH v2 00/10] Enable undefined behavior sanitizer

[Tom Tromey <tom at tromey dot com>]

This is v2 of the series to enable the undefined behavior sanitizer
for gdb.  This is done by default in development mode, but can be
disabled.

I believe this version addresses all the review comments.

Tested (*) by the buildbot.

(*) However, as I mentioned in another thread, the s390 builders do
not like this series.  I get many, many failures.  Looking at the
gdb.log, though, the failures seem to be coming from libstdc++ debug
mode -- which this series does not enable.

    Here's a link to one such build in case you are curious:

    Full Build URL:
	    <http://gdb-build.sergiodj.net/builders/RHEL-s390x-m64/builds/8180>

    Testsuite log (gdb.sum and gdb.log) URL(s):
	    <http://gdb-build.sergiodj.net/results/RHEL-s390x-m64/try/5f/5fe3f3e4633df1ea76ff24a2732d7c73dc983b90/0/>

Until this is understood I am reluctant to push this series.

Tom