language: Add LanguageName::new_static to reduce allocations (#44380)

Implements a specialized constructor `LanguageName::new_static` for
`&'static str` which reduces allocations.

`LanguageName::new` always backs the underlying `SharedString` with an
owned `Arc<str>` even when a `&'static str` is passed. This makes us
allocate each time we create a new `LanguageName` no matter what.
Creating a specialized constructor for `&'static str` allows us to
essentially construct them for free.

Additional change:
Encourages using explicit constructors to avoid needless allocations.
Currently there were no instances of this trait being called where the
lifetime was not `'static` saving another 48 locations of allocation.

```rust
impl<'a> From<&'a str> for LanguageName {
    fn from(str: &'a str) -> Self {
        Self(SharedString::new(str))
    }
}

// to 

impl From<&'static str> for LanguageName {
    fn from(str: &'static str) -> Self {
        Self(SharedString::new_static(str))
    }
}

```

Release Notes:

- N/A

crates/language/src/buffer_tests.rs

@@ -151,7 +151,7 @@ fn test_select_language(cx: &mut App) {
     let registry = Arc::new(LanguageRegistry::test(cx.background_executor().clone()));
     registry.add(Arc::new(Language::new(
         LanguageConfig {
-            name: LanguageName::new("Rust"),
+            name: LanguageName::new_static("Rust"),
             matcher: LanguageMatcher {
                 path_suffixes: vec!["rs".to_string()],
                 ..Default::default()
@@ -173,7 +173,7 @@ fn test_select_language(cx: &mut App) {
     )));
     registry.add(Arc::new(Language::new(
         LanguageConfig {
-            name: LanguageName::new("Make"),
+            name: LanguageName::new_static("Make"),
             matcher: LanguageMatcher {
                 path_suffixes: vec!["Makefile".to_string(), "mk".to_string()],
                 ..Default::default()
@@ -3728,7 +3728,7 @@ fn ruby_lang() -> Language {
 fn html_lang() -> Language {
     Language::new(
         LanguageConfig {
-            name: LanguageName::new("HTML"),
+            name: LanguageName::new_static("HTML"),
             block_comment: Some(BlockCommentConfig {
                 start: "<!--".into(),
                 prefix: "".into(),

crates/language/src/language.rs

@@ -982,7 +982,7 @@ impl<T> Override<T> {
 impl Default for LanguageConfig {
     fn default() -> Self {
         Self {
-            name: LanguageName::new(""),
+            name: LanguageName::new_static(""),
             code_fence_block_name: None,
             grammar: None,
             matcher: LanguageMatcher::default(),
@@ -2756,9 +2756,9 @@ mod tests {
         assert_eq!(
             languages.language_names(),
             &[
-                LanguageName::new("JSON"),
-                LanguageName::new("Plain Text"),
-                LanguageName::new("Rust"),
+                LanguageName::new_static("JSON"),
+                LanguageName::new_static("Plain Text"),
+                LanguageName::new_static("Rust"),
             ]
         );
 
@@ -2769,9 +2769,9 @@ mod tests {
         assert_eq!(
             languages.language_names(),
             &[
-                LanguageName::new("JSON"),
-                LanguageName::new("Plain Text"),
-                LanguageName::new("Rust"),
+                LanguageName::new_static("JSON"),
+                LanguageName::new_static("Plain Text"),
+                LanguageName::new_static("Rust"),
             ]
         );
 
@@ -2782,9 +2782,9 @@ mod tests {
         assert_eq!(
             languages.language_names(),
             &[
-                LanguageName::new("JSON"),
-                LanguageName::new("Plain Text"),
-                LanguageName::new("Rust"),
+                LanguageName::new_static("JSON"),
+                LanguageName::new_static("Plain Text"),
+                LanguageName::new_static("Rust"),
             ]
         );
 

crates/language/src/language_registry.rs

@@ -43,12 +43,18 @@ impl LanguageName {
         Self(SharedString::new(s))
     }
 
+    pub fn new_static(s: &'static str) -> Self {
+        Self(SharedString::new_static(s))
+    }
+
     pub fn from_proto(s: String) -> Self {
         Self(SharedString::from(s))
     }
+
     pub fn to_proto(&self) -> String {
         self.0.to_string()
     }
+
     pub fn lsp_id(&self) -> String {
         match self.0.as_ref() {
             "Plain Text" => "plaintext".to_string(),
@@ -87,9 +93,9 @@ impl std::fmt::Display for LanguageName {
     }
 }
 
-impl<'a> From<&'a str> for LanguageName {
-    fn from(str: &'a str) -> LanguageName {
-        LanguageName(SharedString::new(str))
+impl From<&'static str> for LanguageName {
+    fn from(str: &'static str) -> Self {
+        Self(SharedString::new_static(str))
     }
 }