upgrade 1.15 to 1.16 breaks printf

[Steve Franks <franks at rudbek dot com>]

Hi,

I just upgraded my arm-elf toolchain from 4.2 to 4.3 and by
association, newlib bumpped a rev also.

I can still toggle led's and the like, so I presume the compiler isn't
broken, but if I call any printf-like functions, processor 'locks up'
(which is to say putting led toggles after printf has no effect).

(1) Did something malloc-related change?  My _sbrk_r implementation is
quite basic - just alloc's until it runs into SP, and I've checked
that sizes are well below avaiable ram - this unmodified code was
viable on gcc 4.2 & newlib 1.15...

(2) Is there any possibility of a printf w/o malloc?  I know malloc is
forbidden on alot of systems (aviation/do-178, misra, fda, etc), and
as an embedded-systems guy, I'd be just as happy to have one less
thing to worry about...although being in a scientific-services
company, I'm loath to lose %llu & %lf....

Thanks for your time,
Steve