fix, completion mostly broken due to change in Laz 1.6-rc1

see http://forum.lazarus.freepascal.org/index.php/topic,30663.msg196486.html#msg196486

src/ce_d2syn.pas

@@ -6,7 +6,7 @@ interface
 
 uses
   Classes, SysUtils, Graphics,
-  SynEditHighlighter, SynEditHighlighterFoldBase,
+  SynEditHighlighter, SynEditHighlighterFoldBase, SynEditTypes,
   ce_dlangutils;
 
 const
@@ -134,6 +134,7 @@ type
     procedure doChanged;
   protected
     function GetRangeClass: TSynCustomHighlighterRangeClass; override;
+    function GetIdentChars: TSynIdentChars; override;
 	published
     property foldKinds:   TFoldKinds read fFoldKinds write setFoldKinds;
     property whites:      TSynHighlighterAttributes read fWhiteAttrib write setWhiteAttrib;
@@ -368,6 +369,11 @@ begin
   result := TSynD2SynRange;
 end;
 
+function TSynD2Syn.GetIdentChars: TSynIdentChars;
+begin
+  result := ['_', 'A'..'Z', 'a'..'z', '0'..'9'];
+end;
+
 procedure TSynD2Syn.doChanged;
 begin
   BeginUpdate;