LeanSanitizer reports two kinds of leaks: direct and indirect. A
leaked block that is pointed to by another leaked block is an
"indirect leak", while one that isn't is a "direct leak". Often,
indirect leaks are just things entrained by the "real" leak, but if
two leaked blocks are in a cycle, then they both end up being
indirect, so we need to report them, too.
This patch makes it so that indirect LSan leaks are treated the same
as direct leaks by Mochitests, which means they will turn the tree
orange. There are a few existing indirect leaks of various severity,
so I had add some suppressions. See those bugs for more details.
