bdiff: avoid pointer arithmetic on void*
MSVC 2008 complains:
mercurial/cext/bdiff.c(106) : error C2036: 'void *' : unknown size
mercurial/cext/bdiff.c(107) : error C2036: 'void *' : unknown size
Maybe it's a gcc extension?
https://stackoverflow.com/questions/
37460579/error-c2036-void-unknown-size
pager.pager=p0 # $TESTTMP/sysrc:4
ui.editor=e1 # $TESTTMP/userrc:2
pager.pager=p2 # $PAGER
ui.editor=e1 # $TESTTMP/userrc:2