Removed unneeded boost implementation of is_base_of

llvm-svn: 140014
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: cdcfbf26dc5ceb6bee6f146f4f405c27f14ebe09
1 file changed