add support to llvm-prof for reading from a bitcode file

llvm-svn: 36836
diff --git a/llvm/tools/opt/opt.cpp b/llvm/tools/opt/opt.cpp
index 6c77085..218e5f0 100644
--- a/llvm/tools/opt/opt.cpp
+++ b/llvm/tools/opt/opt.cpp
@@ -268,12 +268,8 @@
     // Load the input module...
     std::auto_ptr<Module> M;
     if (Bitcode) {
-      MemoryBuffer *Buffer;
-      if (InputFilename == "-") {
-        Buffer = MemoryBuffer::getSTDIN();
-      } else {
-        Buffer = MemoryBuffer::getFile(&InputFilename[0], InputFilename.size());
-      }
+      MemoryBuffer *Buffer
+        = MemoryBuffer::getFileOrSTDIN(&InputFilename[0], InputFilename.size());
       
       if (Buffer == 0)
         ErrorMessage = "Error reading file '" + InputFilename + "'";