gcc_release: For RELEASE_MAJOR 5+ only use the major number in branch name.

gcc_release: For RELEASE_MAJOR 5+ only use the major number in branch name.

	* gcc_release: For RELEASE_MAJOR 5+ only use the major
	number in branch name.  When doing final release of 5+,
	if BASE-VER doesn't match release, but is *.*.1 for the
	one smaller minor version, bump BASE-VER.

From-SVN: r222031