bare-arm/lib: Re-add dummy strstr() and memchr().
bare-arm/lib: Re-add dummy strstr() and memchr().

Needed to build Pycopy.

Change-Id: Ie266e86f5fd7ea5633d87741c75d6804de972fcf
Signed-off-by: Paul Sokolovsky <9dc5061f178bb11813e14f1ed02ba27eaf21fa5d@users.sourceforge.net>

pfalcon/micropython,pfalcon/micropython,pfalcon/micropython,pfalcon/micropython,pfalcon/micropython