devel/bear: Update to 3.0.15

Unlike the dynamic linker included with GNU/Linux distributions, $LIB is
not a token strings that our dynamic linker defines. This update
includes a local patch to fix a runtime problem by hardcoding bear's
$LIB dynamic token with the value 'lib'.

Upstream PR: https://github.com/rizsotto/Bear/issues/409
Release notes: https://github.com/rizsotto/Bear/releases/tag/3.0.15