split getInvokedMethods (#30546)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/30546
factor out this function for later support of quantizing shared types
Test Plan:
test_jit.py, test_quantization.py
Imported from OSS
Differential Revision: D18776304
fbshipit-source-id: f5a736b0f69019cefe17ec4517da1ae5462f78e1
