function to search through @code{load-path}.) It searches for
@var{filename} through @var{path-list}, expanded by one of the optional
@var{suffixes} (string of suffixes separated by @samp{:}s), checking for
-access @var{mode} (0|1|2|4 = exists|executable|writeable|readable),
+access @var{mode} (0|1|2|4 = exists|executable|writable|readable),
default readable.
@code{locate-file} keeps hash tables of the directories it searches