Fix broken ASan builds when switching to ESR 52
Compiling Firefox 52 ESR with GCC and ASan breaks (see https://bugzilla.mozilla.org/show_bug.cgi?id=1272498). Unfortunately the complex fix landed merely days after the code moved to aurora and Mozilla folks were unwilling to uplift it. We need to ship an own patch. Fortunately, a much simpler one is available: https://bug1272498.bmoattachments.org/attachment.cgi?id=8764936.