[constexpr] Use initializer instead of assignment

src/hb-ot-layout-common.hh

@@ -1821,8 +1821,7 @@ struct ClassDefFormat1
     }
     /* TODO Speed up, using set overlap first? */
     /* TODO(iter) Rewrite as dagger. */
-    HBUINT16 k; /* TODO(constexpr) use constructor to initialize. */
-    k = klass;
+    HBUINT16 k {klass};
     const HBUINT16 *arr = classValue.arrayZ;
     for (unsigned int i = 0; i < count; i++)
       if (arr[i] == k && glyphs->has (startGlyph + i))
@@ -1995,8 +1994,7 @@ struct ClassDefFormat2
     }
     /* TODO Speed up, using set overlap first? */
     /* TODO(iter) Rewrite as dagger. */
-    HBUINT16 k; /* TODO(constexpr) use constructor to initialize. */
-    k = klass;
+    HBUINT16 k {klass};
     const RangeRecord *arr = rangeRecord.arrayZ;
     for (unsigned int i = 0; i < count; i++)
       if (arr[i].value == k && arr[i].intersects (glyphs))

src/hb-ot-layout-gsubgpos.hh

@@ -2323,12 +2323,7 @@ struct ChainRule
   {
     c->copy (len);
     for (const auto g : it)
-    {
-      /* TODO(constexpr) Simplify. */
-      HBUINT16 gid;
-      gid = g;
-      c->copy (gid);
-    }
+      c->copy (HBUINT16 {g});
   }
 
   ChainRule* copy (hb_serialize_context_t *c,