search for: hasnonnullattr

...the immutable data stored in the LLVM context. Another idea is to eliminate the use of AttributeList completely from Function, and instead store the attributes of an Argument directly *in* the Argument. The function and return attributes would live on the Function. At the end of the day, `Arg->hasNonNullAttr()` should compile to a load and a bittest. This is a more invasive change that would require more API migration, but again it would avoid more FoldingSet usage. The last two optimizations taken together are particularly nice, because it means that changing enum attributes on functions and argument...