llvm-modextract: Call keep() on the output stream before exiting.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288435 91177308-0d34-0410-b5e6-96231b3b80d8

test/tools/llvm-modextract/single.ll

@@ -4,6 +4,11 @@
 ; RUN: llvm-modextract -b -n 0 -o - %t | llvm-dis | FileCheck %s
 ; RUN: not llvm-modextract -b -n 1 -o - %t 2>&1 | FileCheck --check-prefix=ERROR %s
 
+; RUN: llvm-modextract -n 0 -o %t0 %t
+; RUN: llvm-dis -o - %t0 | FileCheck %s
+; RUN: llvm-modextract -b -n 0 -o %t1 %t
+; RUN: llvm-dis -o - %t1 | FileCheck %s
+
 ; CHECK: define void @f()
 ; ERROR: llvm-modextract: error: module index out of range; bitcode file contains 1 module(s)
 

tools/llvm-modextract/llvm-modextract.cpp

@@ -62,11 +62,13 @@ int main(int argc, char **argv) {
     SmallVector<char, 0> Header;
     BitcodeWriter Writer(Header);
     Out->os() << Header << Ms[ModuleIndex].getBuffer();
+    Out->keep();
     return 0;
   }
 
   std::unique_ptr<Module> M = ExitOnErr(Ms[ModuleIndex].parseModule(Context));
   WriteBitcodeToFile(M.get(), Out->os());
 
+  Out->keep();
   return 0;
 }