There are scenarios where mutually recursive functions may cause the SCC
to contain both read only and write only functions. This removes an
assertion when adding read attributes which caused a crash with a the
provided test case, and instead just doesn't add the attributes.
Patch by Luke Lau <luke.lau@intel.com>
Differential Revision: https://reviews.llvm.org/D60761
llvm-svn: 366090
Johannes Doerfert