Include ARM link register in reg set passed to tracer

Include the LR in the register set passed to the wrapped_tracer
function. This allows the backtrace code to get the caller's symbol even
if unwinding has been disabled or for some reason doesn't work.

Signed-off-by: Jeremy C. Andrus <jeremya@cs.columbia.edu>
support building with clang

currently only enabled on non NDK builds

Signed-off-by: Jeremy C. Andrus <jeremya@cs.columbia.edu>
build system updates

Signed-off-by: Jeremy C. Andrus <jeremya@cs.columbia.edu>
move wrapping logic into perl scripts

also - added some more always/never wrap entry points

Signed-off-by: Jeremy C. Andrus <jeremya@cs.columbia.edu>