[pytorch] handle pybind11 style registration API with code analyzer (#36607)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/36607
PR #36258 and subsequent PRs in the stack switch c10 registrations to
the new pybind11 style registration API. One notable difference from old
c10 registration API is that, operator's namespace is no longer in op
schema string, e.g. "aten::" will be factored out from "aten::conv",
"aten::emtpy" and etc. The namespace string will be declared at the
beginning of registrations with TORCH_LIBRARY / TORCH_LIBRARY_IMPL
macro.
A rather simple fix is to extract namespace string from the name of
enclosing function of registrations, as the TORCH_LIBRARY macro will
always create an init function (per namespace) by appending namespace
string to a common prefix.
Another side effect of the API change is that it adds some debug string
constants to the registration API, and because of factoring out the
namespace part from op name, there is no longer an effect way to
differentiate between real op name and debug strings. A simple
workaround is that we only keep the first string constant it encounters
while BFSing the LLVM IR - the real op name is directly passed into the
registration call while the debug string is indirectly passed via
CppFunction.
These new assumptions might be broken by future changes but it's so simple
to implement to unblock the API work.
Test Plan: Imported from OSS
Differential Revision: D21026008
Pulled By: ljk53
fbshipit-source-id: c8c171d23aaba6d6b7985d342e8797525126a713
