threadlib.m4: remove unneeded comment

m4/threadlib.m4

@@ -292,56 +292,3 @@ AC_DEFUN([gl_DISABLE_THREADS], [
   m4_divert_text([INIT_PREPARE], [gl_use_threads_default=no])
 ])
 
-
-dnl Survey of platforms:
-dnl
-dnl Platform          Available   Compiler    Supports   test-lock
-dnl                   flavours    option      weak       result
-dnl ---------------   ---------   ---------   --------   ---------
-dnl Linux 2.4/glibc   posix       -lpthread       Y      OK
-dnl
-dnl GNU Hurd/glibc    posix
-dnl
-dnl FreeBSD 5.3       posix       -lc_r           Y
-dnl                   posix       -lkse ?         Y
-dnl                   posix       -lpthread ?     Y
-dnl                   posix       -lthr           Y
-dnl
-dnl FreeBSD 5.2       posix       -lc_r           Y
-dnl                   posix       -lkse           Y
-dnl                   posix       -lthr           Y
-dnl
-dnl FreeBSD 4.0,4.10  posix       -lc_r           Y      OK
-dnl
-dnl NetBSD 1.6        --
-dnl
-dnl OpenBSD 3.4       posix       -lpthread       Y      OK
-dnl
-dnl MacOS X 10.[123]  posix       -lpthread       Y      OK
-dnl
-dnl Solaris 7,8,9     posix       -lpthread       Y      Sol 7,8: 0.0; Sol 9: OK
-dnl                   solaris     -lthread        Y      Sol 7,8: 0.0; Sol 9: OK
-dnl
-dnl HP-UX 11          posix       -lpthread       N (cc) OK
-dnl                                               Y (gcc)
-dnl
-dnl IRIX 6.5          posix       -lpthread       Y      0.5
-dnl
-dnl AIX 4.3,5.1       posix       -lpthread       N      AIX 4: 0.5; AIX 5: OK
-dnl
-dnl OSF/1 4.0,5.1     posix       -pthread (cc)   N      OK
-dnl                               -lpthread (gcc) Y
-dnl
-dnl Cygwin            posix       -lpthread       Y      OK
-dnl
-dnl Any of the above  pth         -lpth                  0.0
-dnl
-dnl Mingw             win32                       N      OK
-dnl
-dnl BeOS 5            --
-dnl
-dnl The test-lock result shows what happens if in test-lock.c EXPLICIT_YIELD is
-dnl turned off:
-dnl   OK if all three tests terminate OK,
-dnl   0.5 if the first test terminates OK but the second one loops endlessly,
-dnl   0.0 if the first test already loops endlessly.