[rmkit] make single file header work in impl/no-impl modes

Author: okay

src/rmkit/ui/reflow.cpy

@@ -4,7 +4,7 @@
 namespace ui:
   class ReflowLayout: public ui::Layout:
     public:
-    static unordered_map<Scene, vector<ReflowLayout*>> scene_to_layouts
+    static unordered_map<Scene, vector<ReflowLayout*>> scene_to_layouts = {}
     vector<ReflowLayout*> layouts
 
     class PackedChild:
@@ -75,7 +75,6 @@ namespace ui:
       sl := ReflowLayout::add(w)
       self.center.push_back({sl, NULL, padding})
   ;
-  unordered_map<Scene, vector<ReflowLayout*>> ReflowLayout::scene_to_layouts = {}
 
   class HorizontalReflow: public ReflowLayout:
     public:

src/rmkit/util/lsdir.cpy

@@ -5,7 +5,7 @@
 
 namespace util:
 
-  void sort_by_modified_date(vector<string> &filenames, string dirname):
+  static void sort_by_modified_date(vector<string> &filenames, string dirname):
     struct stat buf
     vector<tuple<int, string>> entries
     for (auto filename : filenames)
@@ -14,16 +14,16 @@ namespace util:
       if(stat(full_path.c_str(), &buf))
         debug "Failed stat() on ", full_path
         continue
-      entries.push_back({buf.st_mtime, filename}) 
+      entries.push_back({buf.st_mtime, filename})
 
     sort(entries.begin(), entries.end())
     filenames.clear()
     for (auto e : entries)
       filenames.push_back(std::get<1>(e))
-    
+
     reverse(filenames.begin(), filenames.end())
 
-  vector<string> lsdir(string dirname, string ext=""):
+  static vector<string> lsdir(string dirname, string ext=""):
     DIR *dir
     struct dirent *ent