IRReader: don't mark MemoryBuffers const

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211883 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Bitcode/Reader/BitcodeReader.cpp

@@ -3406,10 +3406,9 @@ Module *llvm::getStreamedBitcodeModule(const std::string &name,
   return M;
 }
 
-ErrorOr<Module *> llvm::parseBitcodeFile(const MemoryBuffer *Buffer,
+ErrorOr<Module *> llvm::parseBitcodeFile(MemoryBuffer *Buffer,
                                          LLVMContext &Context) {
-  ErrorOr<Module *> ModuleOrErr =
-      getLazyBitcodeModule(const_cast<MemoryBuffer *>(Buffer), Context);
+  ErrorOr<Module *> ModuleOrErr = getLazyBitcodeModule(Buffer, Context);
   if (!ModuleOrErr)
     return ModuleOrErr;
   Module *M = ModuleOrErr.get();