Clean up warnings.

Use (void)var to mark var as used, instead of var = var. The
intent of the self assignment was to avoid a warning, but it ends
up invoking a different warning.

Turn off security warnings for a potentially mutable string being
given as the format string to sprintf(). Though only on macosx
unix targets. All of the strings provided are in fact not mutable,
but this fact is hidden from the compiler due to the strings being
extern in a different object file.

fileio.c

@@ -1489,7 +1489,7 @@ int UZ_EXP UzpInput(pG, buf, size, flag)
     int flag;     /* flag bits (bit 0: no echo) */
 {
     /* tell picky compilers to shut up about "unused variable" warnings */
-    pG = pG; buf = buf; flag = flag;
+    (void)pG; (void)buf; (void)flag;
 
     *size = 0;
     return 0;
@@ -1583,7 +1583,7 @@ int UZ_EXP UzpPassword (pG, rcnt, pwbuf, size, zfn, efn)
 
 #ifndef REENTRANT
     /* tell picky compilers to shut up about "unused variable" warnings */
-    pG = pG;
+    (void)pG;
 #endif
 
     if (*rcnt == 0) {           /* First call for current entry */
@@ -1614,7 +1614,7 @@ int UZ_EXP UzpPassword (pG, rcnt, pwbuf, size, zfn, efn)
 
 #else /* !CRYPT */
     /* tell picky compilers to shut up about "unused variable" warnings */
-    pG = pG; rcnt = rcnt; pwbuf = pwbuf; size = size; zfn = zfn; efn = efn;
+    (void)pG; (void)rcnt; (void)pwbuf; (void)size; (void)zfn; (void)efn;
 
     return IZ_PW_ERROR;  /* internal error; function should never get called */
 #endif /* ?CRYPT */

unix/Makefile

@@ -872,12 +872,12 @@ lynx:		unix_make
 
 # Macintosh MacOS X (Unix-compatible enviroment), using standard compiler
 macosx:	unix_make
-	$(MAKE) unzips CFLAGS="-O3 -Wall -DBSD" LF2=""
+	$(MAKE) unzips CFLAGS="-O3 -Wall -DBSD -DZIP64_SUPPORT -Wno-format-security" LF2=""
 	$(STRIP) $(UNZIPS)
 
 # Macintosh MacOS X (Unix-compatible enviroment), using gcc
 macosx_gcc:	unix_make
-	$(MAKE) unzips CC=gcc CFLAGS="-O3 -Wall -DBSD" LF2=""
+	$(MAKE) unzips CC=gcc CFLAGS="-O3 -Wall -DBSD -DZIP64_SUPPORT Wno-format-security" LF2=""
 	$(STRIP) $(UNZIPS)
 
 # Minix 1.5 PC for the 386.  Invoke as is to use default cc, or as "make