Make sure we walk macro expansion decls to handle
cases where e.g a binding introduces control flow.
This should be a pretty uncommon case since bindings
introduced by macros aren't actually usable when
expanded in local contexts, but handle it all the
same.
Ignore any regions recorded while inside a macro
expansion, but account for any control flow that
may have happened such that the exit count is
correctly adjusted. This allows e.g throwing function
calls to behave correctly within the expansion.
rdar://129081384
We may want to revisit this in the future, but for
now let's avoid profiling code in generated
buffers. To make this work we'll need to come up
with a scheme for writing out the generated buffers
such that tools like `llvm-cov` can reference them.
rdar://109562235
