Stop using GraphArgs for shape env guard source tracking (#90911)
GraphArgs worked fairly well, but it was still missing sources
sometimes. Now, we maintain an auxiliary data structure which we
MUST populate whenever we fakeify a tensor / allocate a bare SymInt.
This should guarantee once and for all that every symbol is available.
Should fix swin_base_patch4_window7_224.
While I was at it, I moved fakeification utility back to builder
as it was only used at once call site.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/90911
Approved by: https://github.com/voznesenskym
