GC triggering performance optimizations

Copy the correct starting heap size at process init.
Interfaces to set GC/managed heap parameters.

Change-Id: If0b1637291e77f9781ae6249c5d0257f659253ca
libcore/luni: Use -fno-strict-aliasing for now

This will be reverted once we have a proper fix.

Change-Id: Iab4663a5f96ff9770371f54697aa872260037ac1
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>