49b9165251
. test74 for mmap functionality . vm: add a mem_file memory type that specifies an mmap()ped memory range, backed by a file . add fdref, an object that keeps track of FD references within VM per process and so knows how to de-duplicate the use of FD's by various mmap()ped ranges; there can be many more than there can be FD's . turned off for now, enable with 'filemap=1' as boot option Change-Id: I640b1126cdaa522a0560301cf6732b7661555672