[binutils-gdb] Bump version to 8.0.50.DATE-git

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 8bb5723165d4e7308fb69b21a95f396f9e61caaf ***

Author: Joel Brobecker <brobecker@adacore.com>
Branch: master
Commit: 8bb5723165d4e7308fb69b21a95f396f9e61caaf

Bump version to 8.0.50.DATE-git

Now that the GDB 8.0 branch has been created, we should bump
the GDB version accordingly.

gdb/ChangeLog:

	GDB 8.0 branch created (725bf5cf125783c2a7ca4ab63d3768e220bab2db):
	* version.in: Bump version to 7.99.90.DATE-git.