implement posix_madvise

Bug: 18472477
Change-Id: I8183de6c281acf69ed5f7f88351b056b9827b162
Restore symbols from <arpa/nameser.h>.

Bug: 18627252
Bug: https://code.google.com/p/android/issues/detail?id=81690
Change-Id: I45b6c09cf2b5aabb80900e267d27cc0ec93d4dd8
Merge "implement posix_madvise"
Merge "Restore symbols from <arpa/nameser.h>."