glm: fix head

Closes #34832.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
Prefer cached_location method over @clone ivar
dub: prefer cached_location method over @clone ivar
qt5: prefer cached_location method over @clone ivar
saltstack: prefer cached_location method over @clone ivar
icdiff 1.5.1
icdiff: add 1.5.1 bottle.