* device/include/string.h: added size_t typedef, changed

* device/include/string.h: added size_t typedef, changed
prototypes to use size_t, eliminated separate reentrant and
non-reentrant declarations, added _memmove declaration
* device/lib/_memcpy.c: changed to use size_t instead of int,
changed /4 to >>2 to avoid division library call
* device/lib/_memcmp.c,
* device/lib/_memset.c,
* device/lib/_strncat.c,
* device/lib/_strncpy.c,
* device/lib/_strncmp.c: changed to use size_t instead of int
* device/lib/_memmove.c: new file (fixed bug #772294)
* device/lib/Makefile.in: added _memmove.c
* device/lib/z80/asm_strings.s: fixed bug #772290
* support/regression/tests/bitfields.c: attempt to fix host assertion
failure on amd64-unknown-linux2.2

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@2881 4a8a32a2-be11-0410-ad9d-d568d2c75423