Merge #5126

5126: Use more of FxHash* r=matklad a=lnicola

```
-rwxr-xr-x 1 me me 37917528 Jun 29 17:26 /home/me/.cargo/bin/rust-analyzer
-rwxr-xr-x 1 me me 37904056 Jun 29 18:14 /home/me/.cargo/bin/rust-analyzer
```

Saved 13.5 KB there :-).

Co-authored-by: Laurențiu Nicola <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/crates/ra_ssr/src/parsing.rs b/crates/ra_ssr/src/parsing.rs
index 90c13dbc2..1ae166d19 100644
--- a/crates/ra_ssr/src/parsing.rs
+++ b/crates/ra_ssr/src/parsing.rs
@@ -165,7 +165,7 @@ fn parse_pattern(pattern_str: &str) -> Result<Vec<PatternElement>, SsrError> {
 /// Checks for errors in a rule. e.g. the replace pattern referencing placeholders that the search
 /// pattern didn't define.
 fn validate_rule(rule: &SsrRule) -> Result<(), SsrError> {
-    let mut defined_placeholders = std::collections::HashSet::new();
+    let mut defined_placeholders = FxHashSet::default();
     for p in &rule.pattern.raw.tokens {
         if let PatternElement::Placeholder(placeholder) = p {
             defined_placeholders.insert(&placeholder.ident);