Fix ByteBuffer performance regression.

Use libcore.io.Memory.memmove for mmaped ByteBuffer and
non-bytearray-backed direct ByteBuffer#put(ByteBuffer)
operations.

Bug: 26989924
Change-Id: I660a7431061efbeeb6880c85f524c6fdffc760a0
(cherry picked from commit 27c702be4464b10bc99900769bc037fe4b0cfb7f)
4 files changed