[llvm-objcopy] Hook up the -V alias to --version, output "GNU strip"

This allows libtool to detect the presence of llvm-strip and use
it with the options --strip-debug and --strip-unneeded.

Also hook up the -V alias for objcopy.

Differential Revision: https://reviews.llvm.org/D54936

llvm-svn: 347731
diff --git a/llvm/tools/llvm-objcopy/CopyConfig.cpp b/llvm/tools/llvm-objcopy/CopyConfig.cpp
index b4ebbc5f..0385782 100644
--- a/llvm/tools/llvm-objcopy/CopyConfig.cpp
+++ b/llvm/tools/llvm-objcopy/CopyConfig.cpp
@@ -226,6 +226,7 @@
   }
 
   if (InputArgs.hasArg(OBJCOPY_version)) {
+    outs() << "llvm-objcopy, compatible with GNU objcopy\n";
     cl::PrintVersionMessage();
     exit(0);
   }
@@ -383,6 +384,7 @@
   }
 
   if (InputArgs.hasArg(STRIP_version)) {
+    outs() << "llvm-strip, compatible with GNU strip\n";
     cl::PrintVersionMessage();
     exit(0);
   }