[llvm-undname] Flush output before demangling.

If an error occurs and we write it to stderr, it could appear
before we wrote the mangled name which we're undecorating.
By flushing stdout first, we ensure that the messages are always
sequenced in the correct order.

llvm-svn: 337645

Author: Zachary Turner

llvm/tools/llvm-undname/llvm-undname.cpp

@@ -62,14 +62,17 @@ int main(int argc, char **argv) {
       // them to the terminal a second time.  If they're coming from redirected
       // input, however, then we should display the input line so that the
       // mangled and demangled name can be easily correlated in the output.
-      if (!sys::Process::StandardInIsUserInput())
+      if (!sys::Process::StandardInIsUserInput()) {
         outs() << Line << "\n";
+        outs().flush();
+      }
       demangle(Line);
       outs() << "\n";
     }
   } else {
     for (StringRef S : Symbols) {
       outs() << S << "\n";
+      outs().flush();
       demangle(S);
       outs() << "\n";
     }