am 223ddfcf: Merge "libc: Add missing pipe2() declaration and implementation." into gingerbread

Merge commit '223ddfcfc4cb354641e70da31a60556248db5036' into gingerbread-plus-aosp

* commit '223ddfcfc4cb354641e70da31a60556248db5036':
  libc: Add missing pipe2() declaration and implementation.