Rewrite #includes for llvm/Foo.h to llvm/IR/Foo.h as appropriate to reflect the
migration in r171366.

I don't know anything about lldb, but a force run of the build bot indicated it
would need this patch. I'll try to watch the build bot to get it green.


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@171374 91177308-0d34-0410-b5e6-96231b3b80d8