prevent to check for final attribs inside templates

since they might be mixed or not, in structs or not

src/analysis/final_attribute.d

@@ -110,6 +110,16 @@ public:
         _parent = saved;
     }
 
+    override void visit(const(MixinTemplateDeclaration) mtd)
+    {
+        // can't really know where it'll be mixed (class |final class | struct ?)
+    }
+
+    override void visit(const(TemplateDeclaration) mtd)
+    {
+        // regular template are also mixable
+    }
+
     override void visit(const(Declaration) d)
     {
         const Parent savedParent = _parent;
@@ -266,6 +276,13 @@ public:
         }
     }, sac);
 
+    assertAnalyzerWarnings(q{
+        mixin template Impl()
+        {
+            protected final void mixin_template_can() {}
+        }
+    }, sac);
+
     // fail
 
     assertAnalyzerWarnings(q{