[Driver] Ignore -fno-semantic-interposition
Fedora wants to build projects with -fno-semantic-interposition (e.g.
which is supported by GCC>=5.
Clang's current behavior is similar to -fno-semantic-interposition and
the end goal is to make it more so
Ignore this option.
We should let users know -fsemantic-interposition is not currently
supported, so it should remain a hard error.
Reviewed By: serge-sans-paille
Differential Revision: https://reviews.llvm.org/D72724