llvm-symbolizer: don't leave dangling pointers after flushing LLVMSymbolizer. Add a destructor.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185154 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-symbolizer/LLVMSymbolize.h b/tools/llvm-symbolizer/LLVMSymbolize.h
index d1f2285..03c765c 100644
--- a/tools/llvm-symbolizer/LLVMSymbolize.h
+++ b/tools/llvm-symbolizer/LLVMSymbolize.h
@@ -48,6 +48,9 @@
   };
 
   LLVMSymbolizer(const Options &Opts = Options()) : Opts(Opts) {}
+  ~LLVMSymbolizer() {
+    flush();
+  }
 
   // Returns the result of symbolization for module name/offset as
   // a string (possibly containing newlines).