When global <sys/mman.h> was removed from tile.h it also removed
<unistd.h> nearby. This exposes the lack of <unistd.h> being
included where needed using APIs like close()/read()/unlink()/isatty()
the WASM build seems to show this as the header file set is structured
differently.
This commit related to the dynamic creation of data that is used
to parse commands and options via Lookup.
windows/windows.h: Lookup() constify call-site
tcltk/tclmagic.c: Lookup() constify call-site
graphics/W3Dmain.c: Lookup() constify call-site
windows/windSend.c: Lookup() constify call-site
windows/windMain.c: Lookup() constify call-site
windows/windInt.h: Lookup() constify call-site
textio/txMain.c: Lookup() constify call-site