search for: memref_b

Thanks for the heads up Philip ! I did come across a strange case where LLVM allowed "%" to be a part of a function's name. This was in the context of my patch https://reviews.llvm.org/D33985, where I prefix the name of the source function and the Scop ( A special kind of Region that Polly can optimize, the name of the Scop is the name of the Region ) to the name of the PTX kernel