This commit adds support for recursive function calls to One-Shot
Bufferize.
The analysis does not support recursive function calls. The function
body itself can be analyzed, but we cannot make any assumptions about
the aliasing relation between function result and function arguments.
Similarly, when looking at a `call` op, we do not know whether the
operands will bufferize to a memory read/write. In the absence of such
information, we have to conservatively assume that they do.
This commit is in preparation of removing the deprecated
`func-bufferize` pass. That pass can bufferize recursive functions.
c271ba7f79