Add mmap (memory map) support

Packages describing “mmap” as local USE flag

Package“mmap” Flag Description
dev-haskell/juicypixelsEnable the file loading via mmap (memory map)
media-libs/xine-libUse mmap() function while reading file from local disks. Using mmap() will use more virtual memory space, but leaves to the Kernel the task of caching the file's data. mmap() access should be faster, but might misbehave if the device where the file resides in is removed during playback.
net-dns/nsdUse mmap(2) instead of malloc(3); currently experimental

All packages providing a “mmap” USE flag (3)