Add flash9 backtrace

std/haxe/unit/TestResult.hx

@@ -71,6 +71,11 @@ class TestResult {
 					buf.add(test.backtrace);
 					buf.add("\n");
 				}
+				#else flash9
+				if( test.backtrace != null ){
+					buf.add(test.backtrace);
+					buf.add("\n");
+				}
 				#end
 
 				buf.add("\n");

std/haxe/unit/TestRunner.hx

@@ -147,6 +147,9 @@ class TestRunner {
 							t.currentTest.backtrace = e.stack;
 						}
 					}
+					#else flash9
+					if( e != null && Std.is(e,untyped __global__["Error"] ) )
+						t.currentTest.backtrace = e.getStackTrace();					
 					#end
 				}
 				result.add(t.currentTest);

std/haxe/unit/TestStatus.hx

@@ -40,6 +40,8 @@ class TestStatus {
 	public var backtrace : Array<StackItem>;
 	#else js
 	public var backtrace : Dynamic;
+	#else flash9
+	public var backtrace : String;
 	#end
 
 	public function new() 	{