[dsymutil] Replace TimeValue with TimePoint

Summary:
All changes are pretty straight-forward. I chose to use TimePoints with
second precision, as that is all that seems to be required here.

Reviewers: friss, zturner

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D25908

llvm-svn: 286358
diff --git a/llvm/tools/dsymutil/DwarfLinker.cpp b/llvm/tools/dsymutil/DwarfLinker.cpp
index 9c446f4..aa76905 100644
--- a/llvm/tools/dsymutil/DwarfLinker.cpp
+++ b/llvm/tools/dsymutil/DwarfLinker.cpp
@@ -3294,7 +3294,7 @@
     sys::path::append(Path, Filename);
   BinaryHolder ObjHolder(Options.Verbose);
   auto &Obj =
-      ModuleMap.addDebugMapObject(Path, sys::TimeValue::PosixZeroTime());
+      ModuleMap.addDebugMapObject(Path, sys::TimePoint<std::chrono::seconds>());
   auto ErrOrObj = loadObject(ObjHolder, Obj, ModuleMap);
   if (!ErrOrObj) {
     // Try and emit more helpful warnings by applying some heuristics.