Eliminate 'casting signed to bigger unsigned int' CSA warning

Eliminate 'casting signed to bigger unsigned int' CSA warning

* cord/cordprnt.c (CORD_vsprintf): Cast prec, width, max_size, res
local variables to unsigned.
* cord/tests/cordtest.c (test_basics): Change type of i local variable
from int to size_t; cast c local variable to unsigned char.
* dbg_mlc.c (GC_store_debug_info_inner): Do not cast linenum parameter.
* include/private/dbg_mlc.h (oh.oh_string, oh.oh_int): Refine comment.
* include/private/dbg_mlc.h (oh.oh_int): Change type from word to
signed_word.
* misc.c [!GC_GET_HEAP_USAGE_NOT_NEEDED] (fill_prof_stats): Cast
GC_markers_m1 to signed_word first.
* misc.c (GC_init): Cast space_divisor local variable to unsigned
(instead of word).
* misc.c [!MSWIN32 && !MSWINCE && !OS2 && !MACOS && !GC_ANDROID_LOG]
(GC_write): Cast bytes_written local variable to unsigned (instead of
size_t).