Merge #7513

7513: NFA parser for mbe matcher r=matklad a=edwin0cheng

Almost straight porting from rustc one, but a little bit slow :(

```
rust-analyzer analysis-stats -q . 
```

From:
```log
Database loaded:     636.11ms, 277minstr
  crates: 36, mods: 594, decls: 11527, fns: 9017
Item Collection:     10.99s, 60ginstr
  exprs: 249618, ??ty: 2699 (1%), ?ty: 2101 (0%), !ty: 932
Inference:           28.94s, 123ginstr
Total:               39.93s, 184ginstr
```

To:
```log
Database loaded:     630.90ms, 277minstr
  crates: 36, mods: 594, decls: 11528, fns: 9018
Item Collection:     13.70s, 77ginstr
  exprs: 249482, ??ty: 2699 (1%), ?ty: 2101 (0%), !ty: 932
Inference:           30.27s, 133ginstr
Total:               43.97s, 211ginstr
```

Fixes #4777

Co-authored-by: Edwin Cheng <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 739edb932..ec5aecfa0 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -879,6 +879,7 @@ dependencies = [
  "profile",
  "rustc-hash",
  "smallvec",
+ "stdx",
  "syntax",
  "test_utils",
  "tt",