rust-matchers: add support for `exactmatcher` in `dirstate.status`
`exactmatcher` is the name in the Python implementation and corresponds to
`FileMatcher` in Rust.
Differential Revision: https://phab.mercurial-scm.org/D7531
BasedOnStyle: LLVM
IndentWidth: 8
UseTab: ForIndentation
BreakBeforeBraces: Linux
AllowShortIfStatementsOnASingleLine: false
IndentCaseLabels: false
AllowShortBlocksOnASingleLine: false
AllowShortFunctionsOnASingleLine: false
IncludeCategories:
- Regex: '^<'
Priority: 1
- Regex: '^"'
Priority: 2