Installation into 'const' directory

[Art Haas]

Hi.

This morning's build of GCC mainline installed various files into a
directory named 'const' instead of a version number like name. The c++
headers from yesterday's build were in a '4.1.0' directory, for example.
A perusal of the ChangeLog suggests yesterday's patchset that revamped
the build to use BASE-VER, DATESTAMP, and DEV-PHASE files is likely to
have made this (unanticipated?) change.

Art Haas
-- 
Man once surrendering his reason, has no remaining guard against absurdities
the most monstrous, and like a ship without rudder, is the sport of every wind.

-Thomas Jefferson to James Smith, 1822