__get_sp is missing a return! I don't know how it ever worked.
Use "bx lr" since it works in all cases (armp and thumb).
Change-Id: I26011db333a8a5f96276be83e18da7507c501c38
Reviewed-on: http://gerrit.rockbox.org/206
Reviewed-by: Marcin Bukat <marcin.bukat@gmail.com>
Simplified stack unwinder for ARM. This is port of
http://www.mcternan.me.uk/ArmStackUnwinding/
backtrace() is called from UIE() on native targets
and from panicf() on both native and ARM RaaA.
Change-Id: I8e4b3c02490dd60b30aa372fe842d193b8929ce0
