libnh: fix native build of libnh.a on macOS

Fixes four issues that prevented `make WANT_LIBNH=1 all` from producing
a libnh.a that could be linked into a host program on macOS.  Before
these patches, it built but the resulting archive was unusable: macOS
ld errored on a nested liblua archive member, was missing date.o and
hacklib symbols (`populate_nomakedefs`, `eos`, `lcase`, `mungspaces`,
...), and had duplicate definitions of `main`, `whoami`, etc.

Specific changes:

1. sys/libnh/libnhmain.c: drop `static` on `whoami()`.  src/earlyarg.c
   declares it `extern` and calls it from `scores_only()`; the static
   makes it file-local and that reference goes unresolved.

2. sys/libnh/libnhmain.c: gate the emscripten-only code in get_nhuuid
   with `#ifdef __EMSCRIPTEN__` instead of `#ifdef NHUUID`.  The macOS
   hints define NHUUID for the libnh build (they did so unconditionally
   before NO_NHUUID even existed), so on native builds the compiler
   tried to call `emscripten_run_script_int` / `_string` and failed
   with implicit-function-declaration errors.  __EMSCRIPTEN__ is the
   real signal for "this is being cross-compiled to WASM."

3. sys/unix/hints/macOS.500: in the WANT_LIBNH block, add an explicit
   `recover: lua_support` dependency (gated by MAKEFILE_TOP).  When
   $(GAME) is overridden to empty, the regular `recover: $(GAME)` chain
   no longer triggers `lua_support`, so include/nhlua.h never gets
   generated and recover.c's transitive #include of hack.h fails.

4. sys/unix/hints/macOS.500: rewrite the libnh.a rule.  The previous
   `ar rcs libnh.a $(HOBJ) $(LIBNHSYSOBJ) liblua-$(LUA_VERSION).a` had
   four problems: (a) ar archives liblua.a as a single opaque member
   that macOS ld can't dereference, (b) date.o (DATE_O, kept separate
   from HOBJ) was never archived, so `populate_nomakedefs` and
   `nomakedefs` were missing, (c) hacklib.a was likewise omitted, and
   (d) HOBJ already contains $(SYSOBJ) (with unixmain.o) and $(WINOBJ)
   (the tty windowport), which duplicated symbols from libnhmain.o /
   winshim.o.

   The fix uses `libtool -static` so hacklib.a and liblua's archive
   have their members merged rather than nested, depends on $(LUALIB)
   so lua_support runs first, includes $(DATE_O) and $(TARGET_HACKLIB),
   and uses $(filter-out $(SYSOBJ) $(WINOBJ),$(HOBJ)) to drop the
   duplicates.

Verified by clean rebuild on macOS 26 (arm64, Apple clang 17):
  make spotless
  make fetch-Lua
  make WANT_LIBNH=1 all
and link-tested with a tiny harness that calls
shim_graphics_set_callback() against the resulting libnh.a.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

sys/libnh/libnhmain.c

@@ -37,7 +37,7 @@ extern struct passwd *getpwnam(const char *);
 #ifdef CHDIR
 static void chdirx(const char *, boolean);
 #endif /* CHDIR */
-static boolean whoami(void);
+boolean whoami(void);
 static void process_options(int, char **);
 
 #ifdef _M_UNIX
@@ -516,7 +516,7 @@ chdirx(const char *dir, boolean wr)
 #endif /* CHDIR */
 
 /* returns True iff we set plname[] to username which contains a hyphen */
-static boolean
+boolean
 whoami(void)
 {
     /*
@@ -805,7 +805,7 @@ get_nhuuid(void)
                              0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
     char *uuid = (char *) &stmp[0];
 #ifndef NONHUUID
-#ifdef NHUUID
+#ifdef __EMSCRIPTEN__
     int uuid_available = 0;
 #endif
 #endif
@@ -814,7 +814,7 @@ get_nhuuid(void)
         return;
 
 #ifndef NONHUUID
-#ifdef NHUUID
+#ifdef __EMSCRIPTEN__
     uuid_available = emscripten_run_script_int(
 		    "typeof crypto !== 'undefined'"
 		    " && typeof crypto.randomUUID === 'function'");
@@ -824,7 +824,7 @@ get_nhuuid(void)
             uuid = (char *) &stmp[0];
         }
     }
-#endif  /* NHUUID */
+#endif  /* __EMSCRIPTEN__ */
 #endif  /* NONHUUID */
     Snprintf(svn.nhuuid, sizeof svn.nhuuid, "%s", uuid);
 }

sys/unix/hints/macOS.500

@@ -345,6 +345,12 @@ LIBNHSYSOBJ = $(TARGETPFX)libnhmain.o $(TARGETPFX)ioctl.o \
 #without winshim
 override GAME=
 MOREALL += ( cd src ; $(MAKE) pregame ; $(MAKE) $(TARGETPFX)libnh.a )
+# With $(GAME) empty, the regular `recover: $(GAME)` chain no longer
+# triggers lua_support, but recover.c still pulls in hack.h -> nhlua.h
+# transitively.  Make recover depend on lua_support explicitly.
+ifdef MAKEFILE_TOP
+recover: lua_support
+endif
 endif  # WANT_LIBNH
 
 # Lua
@@ -568,8 +574,20 @@ $(TARGETPFX)macuuid.o: ../sys/unix/macuuid.m
 endif
 
 ifdef WANT_LIBNH
-$(TARGETPFX)libnh.a: $(HOBJ) $(LIBNHSYSOBJ) ../lib/lua/liblua-$(LUA_VERSION).a
-	$(AR) rcs $@ $(HOBJ) $(LIBNHSYSOBJ) ../lib/lua/liblua-$(LUA_VERSION).a
+# Build libnh.a by merging the engine objects, the shim windowport,
+# date.o (separate from $(HOBJ) per Makefile.src), hacklib.a, and Lua's
+# static archive.  Use libtool -static rather than ar so hacklib.a and
+# liblua-$(LUA_VERSION).a have their members merged in -- ar would archive
+# them as opaque .a members and macOS ld can't dereference those.
+# Depending on $(LUALIB) triggers the lua_support build (which generates
+# include/nhlua.h); without it, $(HOBJ) won't compile.
+# filter-out drops $(SYSOBJ) (which carries unixmain.o) and $(WINOBJ) (the
+# tty windowport) from $(HOBJ); $(LIBNHSYSOBJ) supplies libnhmain.o and
+# winshim.o in their place.
+$(TARGETPFX)libnh.a: $(LUALIB) $(HOBJ) $(LIBNHSYSOBJ) $(DATE_O) $(TARGET_HACKLIB)
+	libtool -static -o $@ \
+		$(filter-out $(SYSOBJ) $(WINOBJ),$(HOBJ)) \
+		$(LIBNHSYSOBJ) $(DATE_O) $(TARGET_HACKLIB) $(LUALIB)
 	@echo "$@ built."
 $(TARGETPFX)libnhmain.o : ../sys/libnh/libnhmain.c $(HACK_H)
 	$(CC) $(CFLAGS) -c -o$@ $<