Bug 1044414 - Add a fallback for unknown platforms after bug 945869. r=ted
Bug 1046045 - Remove ${srcroot} from cfghdrs_in, cfgoutputs_in and cfghdrs_tup in jemalloc's configure. r=mshal
Bug 1045969 - Use paths relative to root topobjdir for backend files for similar reasons as in bug 1045329. r=mshal

and paths relative to the "local" topobjdir for linkage.