flex: modernize
flex: add test

Closes #35328.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
postgis 2.1.5

Version bump.

Closes #35329.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
bison: modernize
bison: add test

Closes #35330.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
asciidoc: modernize
asciidoc: add test

Closes #35331.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>