tests: allow Google's internal builds of clang-format to be used
These builds do not actually include any Google-specific formatting changes; the
only reason they don't include the LLVM version number is due to a decision to
elide the version number from *all* LLVM/clang projects.
For most builds of clang-format, even "unofficial" ones, the LLVM version will
be displayed; example:
```
clang-format version 14.0.0 (https://github.com/llvm/llvm-project.git 1830ec94ac022ae0b6d6876fc2251e6b91e5931e)
```
The Google-internal build looks like this:
```
clang-format version google3-trunk (1830ec94ac022ae0b6d6876fc2251e6b91e5931e)
```
Differential Revision: https://phab.mercurial-scm.org/D10538
test sparse
$ hg init myrepo
$ cd myrepo
$ cat >> $HGRCPATH <<EOF
> [extensions]
> sparse=
> purge=
> strip=
> rebase=
> EOF
$ echo a > index.html
$ echo x > data.py
$ echo z > readme.txt
$ cat > base.sparse <<EOF
> [include]
> *.sparse
> EOF
$ hg ci -Aqm 'initial'
$ cat > webpage.sparse <<EOF
> %include base.sparse
> [include]
> *.html
> EOF
$ hg ci -Aqm 'initial'
Clear rules when there are includes
$ hg debugsparse --include *.py
$ ls -A
.hg
data.py
$ hg debugsparse --clear-rules
$ ls -A
.hg
base.sparse
data.py
index.html
readme.txt
webpage.sparse
Clear rules when there are excludes
$ hg debugsparse --exclude *.sparse
$ ls -A
.hg
data.py
index.html
readme.txt
$ hg debugsparse --clear-rules
$ ls -A
.hg
base.sparse
data.py
index.html
readme.txt
webpage.sparse
Clearing rules should not alter profiles
$ hg debugsparse --enable-profile webpage.sparse
$ ls -A
.hg
base.sparse
index.html
webpage.sparse
$ hg debugsparse --include *.py
$ ls -A
.hg
base.sparse
data.py
index.html
webpage.sparse
$ hg debugsparse --clear-rules
$ ls -A
.hg
base.sparse
index.html
webpage.sparse