This change extends the current logic for inferring readonly and readnone argument attributes to also infer writeonly.
This change is deliberately minimal; there's a couple of areas for follow up.
* I left out all call handling and thus any benefit from the SCC walk. When examining the test changes, I realized the existing code is imprecise, and am going to fix that in it's own revision before adding in the writeonly handling. (Mostly because updating the tests is hard when I, the human, can't figure out whether the result is correct.)
* I left out handling for storing a value (as opposed to storing to a pointer). This should benefit readonly/readnone as well, and applies to a bunch of other instructions. Seemed worth having as a separate review.
Differential Revision: https://reviews.llvm.org/D114963
clang itself. This dates back to clang's early days and while it looks like
some of it is still used (for kext for example), other parts are probably dead.
Remove the -ccc-clang-archs option and associated code. I don't think there
is any remaining setup where clang doesn't support an architecture but it can
expect an working gcc cross compiler to be available.
A nice side effect is that tests no longer need to differentiate architectures
that are included in production builds of clang and those that are not.
llvm-svn: 165545
Philip Reames