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: Ic1e73bf7713c9eb3f0a0c40144c1dea7e2bd4388
Signed-off-by: zwliew <zhaoweiliew@gmail.com>