bionic: Fix aliasing violations

This makes bionic compile with compilers enforcing
strict adherence to aliasing rules (e.g. gcc 4.6+
with -Wstrict-aliasing=2 -Werror=strict-aliasing).

Change-Id: I389e96a01aa84244f80c972fc50b3678f6e46b50
Signed-off-by: zwliew <zhaoweiliew@gmail.com>