Highlight never type as BuiltinType

Author: Veykril

crates/ide/src/syntax_highlighting.rs

@@ -562,6 +562,9 @@ fn highlight_element(
             T![!] if element.parent().and_then(ast::MacroCall::cast).is_some() => {
                 HighlightTag::Macro.into()
             }
+            T![!] if element.parent().and_then(ast::NeverType::cast).is_some() => {
+                HighlightTag::BuiltinType.into()
+            }
             T![*] if element.parent().and_then(ast::PtrType::cast).is_some() => {
                 HighlightTag::Keyword.into()
             }

crates/ide/src/syntax_highlighting/test_data/highlighting.html

@@ -110,6 +110,10 @@
     <span class="function">foo</span><span class="operator">::</span><span class="punctuation">&lt;</span><span class="lifetime">'a</span><span class="punctuation">,</span> <span class="builtin_type">i32</span><span class="punctuation">&gt;</span><span class="punctuation">(</span><span class="punctuation">)</span>
 <span class="punctuation">}</span>
 
+<span class="keyword">fn</span> <span class="function declaration">never</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="operator">-&gt;</span> <span class="builtin_type">!</span> <span class="punctuation">{</span>
+    <span class="keyword control">loop</span> <span class="punctuation">{</span><span class="punctuation">}</span>
+<span class="punctuation">}</span>
+
 <span class="keyword">use</span> <span class="module">ops</span><span class="operator">::</span><span class="trait">Fn</span><span class="punctuation">;</span>
 <span class="keyword">fn</span> <span class="function declaration">baz</span><span class="punctuation">&lt;</span><span class="type_param declaration">F</span><span class="punctuation">:</span> <span class="trait">Fn</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="operator">-&gt;</span> <span class="punctuation">(</span><span class="punctuation">)</span><span class="punctuation">&gt;</span><span class="punctuation">(</span><span class="value_param declaration callable">f</span><span class="punctuation">:</span> <span class="type_param">F</span><span class="punctuation">)</span> <span class="punctuation">{</span>
     <span class="value_param callable">f</span><span class="punctuation">(</span><span class="punctuation">)</span>
@@ -179,6 +183,8 @@
 
     <span class="keyword">let</span> <span class="variable declaration">baz</span> <span class="operator">=</span> <span class="numeric_literal">-</span><span class="numeric_literal">42</span><span class="punctuation">;</span>
     <span class="keyword">let</span> <span class="variable declaration">baz</span> <span class="operator">=</span> <span class="operator">-</span><span class="variable">baz</span><span class="punctuation">;</span>
+
+    <span class="keyword">let</span> <span class="punctuation">_</span> <span class="operator">=</span> <span class="operator">!</span><span class="bool_literal">true</span><span class="punctuation">;</span>
 <span class="punctuation">}</span>
 
 <span class="keyword">enum</span> <span class="enum declaration">Option</span><span class="punctuation">&lt;</span><span class="type_param declaration">T</span><span class="punctuation">&gt;</span> <span class="punctuation">{</span>

crates/ide/src/syntax_highlighting/tests.rs

@@ -84,6 +84,10 @@ fn foo<'a, T>() -> T {
     foo::<'a, i32>()
 }
 
+fn never() -> ! {
+    loop {}
+}
+
 use ops::Fn;
 fn baz<F: Fn() -> ()>(f: F) {
     f()
@@ -153,6 +157,8 @@ fn main() {
 
     let baz = -42;
     let baz = -baz;
+
+    let _ = !true;
 }
 
 enum Option<T> {