Merge #5345

5345: Semantic Highlighting: Emit mutable modifier for 'self' when applicable r=matklad a=Veykril

This PR implements emitting the mutable modifier for the self keyword when applicable for semantic highlighting as mentioned in #5041. The rendered highlighting test html file:
![firefox_5lbsFNBqsT](https://user-images.githubusercontent.com/3757771/87346245-a5a07280-c551-11ea-9051-e5901255f8c9.png)
As you can see it does not emit the modifier when `self` is not used in a mutable context even if it is declared mutably in the enclosing function. I'm not sure if this is actually something wanted or not.

Co-authored-by: Lukas Wirth <[email protected]>

1 files changed, 10 insertions, 0 deletions

diff --git a/crates/ra_ide/test_data/highlighting.html b/crates/ra_ide/test_data/highlighting.html
index 134743c72..553811a2f 100644
--- a/crates/ra_ide/test_data/highlighting.html
+++ b/crates/ra_ide/test_data/highlighting.html
@@ -51,6 +51,16 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     }
 }
 
+<span class="keyword">impl</span> <span class="struct">Foo</span> {
+    <span class="keyword">fn</span> <span class="function declaration">baz</span>(<span class="keyword">mut</span> <span class="self_keyword mutable">self</span>) -&gt; <span class="builtin_type">i32</span> {
+        <span class="self_keyword">self</span>.<span class="field">x</span>
+    }
+
+    <span class="keyword">fn</span> <span class="function declaration">qux</span>(&<span class="keyword">mut</span> <span class="self_keyword mutable">self</span>) {
+        <span class="self_keyword mutable">self</span>.<span class="field">x</span> = <span class="numeric_literal">0</span>;
+    }
+}
+
 <span class="keyword">static</span> <span class="keyword">mut</span> <span class="static declaration mutable">STATIC_MUT</span>: <span class="builtin_type">i32</span> = <span class="numeric_literal">0</span>;
 
 <span class="keyword">fn</span> <span class="function declaration">foo</span>&lt;<span class="lifetime declaration">'a</span>, <span class="type_param declaration">T</span>&gt;() -&gt; <span class="type_param">T</span> {