upstream #931

Job	Run time
html5lib-tests	55s
ruby-head-valgrind (enable)	4m 35s
jruby-head	1m 13s
ruby-head-valgrind (disable)	6m 58s
ruby-head (ubuntu, enable)	43s
ruby-head (ubuntu, disable)	2m 53s
truffleruby-head (--disable-system-libraries --disable-static)	3m 26s
truffleruby-head (--disable-system-libraries --enable-static)	5m 15s
xmlsoft-head (ubuntu)	1m 41s
ruby-head (windows, enable)	3m 23s
truffleruby-head (--enable-system-libraries)	2m 33s
xmlsoft-head (windows)	10m 29s
xmlsoft-head-valgrind	6m 24s
ruby-head (windows, disable)	5m 16s
xmlsoft-head (macos)	3m 12s
ruby-head (macos, enable)	3m 5s
ruby-head (macos, disable)	1m 28s
	1h 3m 29s

Provide feedback