don't break reading from stdin


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36336 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-dis/llvm-dis.cpp b/tools/llvm-dis/llvm-dis.cpp
index 7a8bf5a..bb91ad6 100644
--- a/tools/llvm-dis/llvm-dis.cpp
+++ b/tools/llvm-dis/llvm-dis.cpp
@@ -54,8 +54,9 @@
     std::string ErrorMessage;
 
     std::auto_ptr<Module> M;
-    
-    M.reset(ParseBitcodeFile(InputFilename, &ErrorMessage));
+   
+    if (InputFilename != "-") 
+      M.reset(ParseBitcodeFile(InputFilename, &ErrorMessage));
     
     if (M.get() == 0)
       M.reset(ParseBytecodeFile(InputFilename,Compressor::decompressToNewBuffer,