Merge r309860 from stable/9, as this also applies to stable/10:

Merge r309860 from stable/9, as this also applies to stable/10:

Fix libllvmanalysis build failure after r309857: on stable/9, llvm is
compiled by gcc, and without -std=c++11, so the nullptr keyword is
unknown.  Use the old-school plain zero syntax instead.

git-svn-id: svn://svn.freebsd.org/base/stable/10@310082 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f