Fixed forum-17221: ArgumentOutOfRangeException when opening large C# files (>=46341 lines) with XML documentation comments.

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/branches/2.1@2530 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/Main/ICSharpCode.SharpDevelop.Dom/Project/Src/NRefactoryResolver/NRefactoryASTConvertVisitor.cs

@@ -128,7 +128,7 @@ namespace ICSharpCode.SharpDevelop.Dom.NRefactoryResolver
 					else
 						break;
 				} else {
-					m = left + (line - leftLine) * (right - left) / (rightLine - leftLine);
+					m = (int)(left + Math.BigMul((line - leftLine), (right - left)) / (rightLine - leftLine));
 				}
 				
 				int mLine = specials[m].StartPosition.Y;