In the past the "-ftree-loop-linear" switch provided a measurable
improvement in performance for certain functions.  At some point it
was assigned as the responsibility of Graphite in GCC.  It has been
found that even with Graphite enabled these flags no longer perform
any appreciable improvement over the baseline.

Graphite now has some open bugs which need to be fixed in order for it
to provide measurable performance improvements but it lacks active
development.  As a result some compiler distributors may disable
Graphite.  If Graphite is disabled then building GLIBC will fail if
the "-ftree-loop-linear" switch is used.

This patch removes the use of "-ftree-loop-linear" as unnecessary.