[LTO] Call InitLLVM from llvm-lto2

Summary:
D45602 added this to most tools, including llvm-lto, but not to
llvm-lto2. Add it there and test that it works in both lto tools.

Reviewers: ruiu

Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D53330

llvm-svn: 344631
diff --git a/llvm/tools/llvm-lto2/llvm-lto2.cpp b/llvm/tools/llvm-lto2/llvm-lto2.cpp
index 442973f..2642636 100644
--- a/llvm/tools/llvm-lto2/llvm-lto2.cpp
+++ b/llvm/tools/llvm-lto2/llvm-lto2.cpp
@@ -23,6 +23,7 @@
 #include "llvm/LTO/LTO.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileSystem.h"
+#include "llvm/Support/InitLLVM.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Support/Threading.h"
 
@@ -388,6 +389,7 @@
 }
 
 int main(int argc, char **argv) {
+  InitLLVM X(argc, argv);
   InitializeAllTargets();
   InitializeAllTargetMCs();
   InitializeAllAsmPrinters();