Fix warnings

This change fixes Cosmopolitan so it has fewer opinions about compiler
warnings. The whole repository had to be cleaned up to be buildable in
-Werror -Wall mode. This lets us benefit from things like strict const
checking. Some actual bugs might have been caught too.

third_party/unzip/fileio.c

@@ -183,8 +183,6 @@ static ZCONST char Far ExtraFieldTooLong[] =
 #else
    static ZCONST char Far DiskFullQuery[] =
      "%s:  write error (disk full?).  Continue? (y/n/^C) ";
-   static ZCONST char Far ZipfileCorrupt[] =
-     "error:  zipfile probably corrupt (%s)\n";
 #  ifdef SYMLINKS
      static ZCONST char Far FileIsSymLink[] =
        "%s exists and is a symbolic link%s.\n";

third_party/unzip/unix.c

@@ -1268,6 +1268,7 @@ int set_symlnk_attribs(__G__ slnk_entry)
     slinkentry *slnk_entry;
 {
     ulg z_uidgid[2];
+    (void)z_uidgid;
 
     if (slnk_entry->attriblen > 0) {
 # if (!defined(NO_LCHOWN))

third_party/unzip/unzip.c

@@ -3626,7 +3626,7 @@ static ZCONST char Far long_op_ambig_err[] =
 static ZCONST char Far long_op_not_sup_err[] =
    "long option '%s' not supported\n";
 
-static ZCONST char Far no_arg_files_err[] = "argument files not enabled\n";
+/* static ZCONST char Far no_arg_files_err[] = "argument files not enabled\n"; */
 
 
 /* below removed as only used for processing argument files */

third_party/unzip/unzip.mk

@@ -50,6 +50,7 @@ o/$(MODE)/third_party/unzip/unzip.com.dbg:					\
 
 $(THIRD_PARTY_UNZIP_A_OBJS): private						\
 		CPPFLAGS +=							\
+			-w							\
 			-DUSE_BZIP2						\
 			-DUNICODE_SUPPORT					\
 			-DHAVE_UNLINK						\