Move torchdynamo start tracing message earlier (#98990)
Currently, it lives inside run(), but this is too late;
we do a lot of work initializing OutputGraph and those log
messages will show up before "start tracing". This is bad.
Now the start of tracing is InstructionTranslator construction,
which ensures we catch these sites.
Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/98990
Approved by: https://github.com/yanboliang
