Color in as a control keyword

Author: georgewfraser

crates/ra_ide/src/snapshots/highlighting.html

@@ -63,6 +63,10 @@
         <span class="static mutable">STATIC_MUT</span> = <span class="numeric_literal">1</span>;
     }
 
+    <span class="keyword control">for</span> <span class="variable declaration">e</span> <span class="keyword control">in</span> <span class="variable mutable">vec</span> {
+        <span class="comment">// Do nothing</span>
+    }
+
     <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable declaration mutable">x</span> = <span class="numeric_literal">42</span>;
     <span class="keyword">let</span> <span class="variable declaration mutable">y</span> = &<span class="keyword">mut</span> <span class="variable mutable">x</span>;
     <span class="keyword">let</span> <span class="variable declaration">z</span> = &<span class="variable mutable">y</span>;

crates/ra_ide/src/syntax_highlighting.rs

@@ -408,7 +408,8 @@ fn highlight_element(
                 | T![loop]
                 | T![match]
                 | T![return]
-                | T![while] => h | HighlightModifier::ControlFlow,
+                | T![while]
+                | T![in] => h | HighlightModifier::ControlFlow,
                 T![unsafe] => h | HighlightModifier::Unsafe,
                 _ => h,
             }

crates/ra_ide/src/syntax_highlighting/tests.rs

@@ -47,6 +47,10 @@ fn main() {
         STATIC_MUT = 1;
     }
 
+    for e in vec {
+        // Do nothing
+    }
+
     let mut x = 42;
     let y = &mut x;
     let z = &y;