[Bug #1505] DL::CPtr#<=> doesn't return -1

Bug #1505: DL::CPtr#<=> doesn’t return -1
http://redmine.ruby-lang.org/issues/show/1505

e$B5/I<<Te(B: Takashi T.
e$B%9%F!<%?%9e(B: Open, e$BM%@hEYe(B: Normal
e$B%+%F%4%je(B: ext, Target version: 1.9.2
ruby -v: ruby 1.9.2dev (2009-05-16 trunk 23440) [i686-linux]

DL::CPtr#<=> e$B$,e(B -1 e$B$G$O$J$/$Fe(B 4294967295 e$B$rJV$7$^$9!#e(B

$ cat d15.rb
require ‘dl’

s = ‘abc’
cptr = DL::CPtr[s]
cptr1 = cptr + 1
p cptr <=> cptr1
p cptr1 <=> cptr

$ ruby-1.9 d15.rb
4294967295
1

e$B%A%1%C%He(B #1505 e$B$,99?7$5$l$^$7$?!#e(B (by Nobuyoshi N.)

e$B%9%F!<%?%9e(B Opene$B$+$ie(BClosede$B$KJQ99e(B
e$B?JD=e(B % 0e$B$+$ie(B100e$B$KJQ99e(B

Applied in changeset r23549.

http://redmine.ruby-lang.org/issues/show/1505