servo: Merge #18171 - Use Parser::skip_whitespace in a few places to …

…make Parser::try rewind less (from servo:skip_whitespace); r=emilio

**Do not merge yet.** This pulls in unrelated cssparser changes which add a dependency to `dota`, and we’d like to resolve dtolnay/dtoa#9 before landing dtoa in mozilla-central. Also, the dependency change may require manually revendoring in mozilla-central.

Gecko’s CSS parsing microbenchmarks before:

```
  43.437 ±  0.391 ms    Stylo.Servo_StyleSheet_FromUTF8Bytes_Bench
  29.244 ±  0.042 ms    Stylo.Gecko_nsCSSParser_ParseSheet_Bench
 281.884 ±  0.028 ms    Stylo.Servo_DeclarationBlock_SetPropertyById_Bench
 426.242 ±  0.008 ms    Stylo.Servo_DeclarationBlock_SetPropertyById_WithInitialSpace_Bench
```

After:

```
  29.779 ±  0.254 ms    Stylo.Servo_StyleSheet_FromUTF8Bytes_Bench
  28.841 ±  0.031 ms    Stylo.Gecko_nsCSSParser_ParseSheet_Bench
 296.240 ±  4.744 ms    Stylo.Servo_DeclarationBlock_SetPropertyById_Bench
 293.855 ±  4.304 ms    Stylo.Servo_DeclarationBlock_SetPropertyById_WithInitialSpace_Bench
```

Source-Repo: https://github.com/servo/servo
Source-Revision: 8812422bfa504633a7011b0b002e9a2682c7d045

UltraBlame original commit: 75a20ebcd6e8c43b2f0c332b6d5ce947ba1f5ad7

servo/components/selectors/Cargo.toml

@@ -184,6 +184,8 @@ cssparser
 0
 .
 19
+.
+3
 "
 log
 =

servo/components/selectors/parser.rs

@@ -8057,51 +8057,12 @@ new
 (
 )
 ;
-loop
-{
-let
-before_this_token
-=
-input
-.
-state
-(
-)
-;
-if
-!
-matches
-!
-(
-input
-.
-next_including_whitespace
-(
-)
-Ok
-(
-&
-Token
-:
-:
-WhiteSpace
-(
-_
-)
-)
-)
-{
 input
 .
-reset
+skip_whitespace
 (
-&
-before_this_token
 )
 ;
-break
-}
-}
 if
 !
 parse_type_selector
@@ -8285,51 +8246,12 @@ Impl
 :
 SelectorImpl
 {
-loop
-{
-let
-before_this_token
-=
-input
-.
-state
-(
-)
-;
-if
-!
-matches
-!
-(
-input
-.
-next_including_whitespace
-(
-)
-Ok
-(
-&
-Token
-:
-:
-WhiteSpace
-(
-_
-)
-)
-)
-{
 input
 .
-reset
+skip_whitespace
 (
-&
-before_this_token
 )
 ;
-break
-}
-}
 let
 mut
 empty

servo/components/style/Cargo.toml

@@ -295,6 +295,8 @@ cssparser
 0
 .
 19
+.
+3
 "
 encoding
 =