Generate escape sequence for non-printable ascii characters

runtime/vm/unit_test.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/unit_test.h"
 
 #include <stdio.h>
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
@@ skipping 209 matching lines @@
   node_sequence_->scope()->AddVariable(temp);
   return temp;
 }
 
 
 bool CompilerTest::TestCompileScript(const Library& library,
                                      const Script& script) {
   Isolate* isolate = Isolate::Current();
   ASSERT(isolate != NULL);
   const Error& error = Error::Handle(Compiler::Compile(library, script));
+  if (!error.IsNull()) {
+    OS::Print("Error compiling test script:\n%s\n",
+    error.ToErrorCString());
+  }
   return error.IsNull();
 }
 
 
 bool CompilerTest::TestCompileFunction(const Function& function) {
   Isolate* isolate = Isolate::Current();
   ASSERT(isolate != NULL);
   ASSERT(ClassFinalizer::AllClassesFinalized());
   const Error& error = Error::Handle(Compiler::CompileFunction(function));
   return error.IsNull();
 }
 
 #endif  // !defined(TARGET_ARCH_ARM64)
 
 }  // namespace dart