Define InitLLVM to do common initialization all at once.

We have a few functions that virtually all command wants to run on
process startup/shutdown. This patch adds InitLLVM class to do that
all at once, so that we don't need to copy-n-paste boilerplate code
to each llvm command's main() function.

Differential Revision: https://reviews.llvm.org/D45602

llvm-svn: 330046
diff --git a/llvm/tools/llvm-objcopy/llvm-objcopy.cpp b/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
index 7d23039..99f0264 100644
--- a/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
+++ b/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
@@ -24,9 +24,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/ErrorOr.h"
 #include "llvm/Support/FileOutputBuffer.h"
-#include "llvm/Support/ManagedStatic.h"
-#include "llvm/Support/PrettyStackTrace.h"
-#include "llvm/Support/Signals.h"
+#include "llvm/Support/InitLLVM.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <cassert>
@@ -327,10 +325,7 @@
 }
 
 int main(int argc, char **argv) {
-  // Print a stack trace if we signal out.
-  sys::PrintStackTraceOnErrorSignal(argv[0]);
-  PrettyStackTraceProgram X(argc, argv);
-  llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
+  InitLLVM X(argc, argv);
   cl::ParseCommandLineOptions(argc, argv, "llvm objcopy utility\n");
   ToolName = argv[0];
   if (InputFilename.empty()) {