rust-revlog: don't create an in-memory nodemap for filelogs from Python...
rust-revlog: don't create an in-memory nodemap for filelogs from Python
Explanations inline.
Benchmarks from this change affect positively the only repo that showed this
being a problem:
```
### data-env-vars.name = mozilla-try-2024-03-26-ds2-pnm
# benchmark.name = hg.command.cat
# bin-env-vars.hg.flavor = rust
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.files = all-root
# benchmark.variants.output = plain
# benchmark.variants.rev = tip
default: 62.848869 ~~~~~
before-this-patch: 58.113051 (-7.54%, -4.74)
this-patch: 57.407533 (-8.66%, -5.44)
### data-env-vars.name = mozilla-try-2024-03-26-ds2-pnm
# benchmark.name = hg.command.log
# bin-env-vars.hg.flavor = rust
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.limit-rev = 10
# benchmark.variants.patch = yes
# benchmark.variants.rev = none
default: 3.173532 ~~~~~
before-this-patch: 3.543591 (+11.66%, +0.37)
this-patch: 3.297235 (+3.90%, +0.12)
```
