Subzero: Allow builds with assertions disabled.

src/IceTimerTree.cpp

Index: src/IceTimerTree.cpp
diff --git a/src/IceTimerTree.cpp b/src/IceTimerTree.cpp
index 4bdb80ab91c34daeef2c439124d52c72f69353c5..fa0e3219a1df767673cda313b6879e0c6d2e8d46 100644
--- a/src/IceTimerTree.cpp
+++ b/src/IceTimerTree.cpp
@@ -12,6 +12,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/Support/Timer.h"
+
 #include "IceDefs.h"
 #include "IceTimerTree.h"
 
@@ -139,4 +141,9 @@ void TimerStack::dump(Ostream &Str) {
   Str << "Number of timer updates: " << StateChangeCount << "\n";
 }
 
+double TimerStack::timestamp() {
+  // TODO: Implement in terms of std::chrono for C++11.
+  return llvm::TimeRecord::getCurrentTime(false).getWallTime();
+}
+
 } // end of namespace Ice