2.40 branch now open for updates

[Joseph Myers]

It looks like version numbers aren't consistently set on the branch at 
present; building from it I get errors of the form:

In file included from /scratch/jmyers/glibc/many12/src/binutils/gprof/gprof.h:41,
                 from /scratch/jmyers/glibc/many12/src/binutils/gprof/basic_blocks.c:24:
./gconfig.h:104: error: "VERSION" redefined [-Werror]
  104 | #define VERSION "2.40.00"
      | 
In file included from /scratch/jmyers/glibc/many12/src/binutils/gprof/../bfd/sysdep.h:29,
                 from /scratch/jmyers/glibc/many12/src/binutils/gprof/gprof.h:33,
                 from /scratch/jmyers/glibc/many12/src/binutils/gprof/basic_blocks.c:24:
../bfd/config.h:327: note: this is the location of the previous definition
  327 | #define VERSION "2.40"

-- 
Joseph S. Myers
joseph@codesourcery.com