Make ToolExecutionError inherit std::exception and implement its

interface: getMessage() is gone, use what() instead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11621 91177308-0d34-0410-b5e6-96231b3b80d8

tools/bugpoint/ToolRunner.cpp

@@ -21,6 +21,8 @@
 #include <sstream>
 using namespace llvm;
 
+ToolExecutionError::~ToolExecutionError() throw() { }
+
 static void ProcessFailure(std::string ProgPath, const char** Args) {
   std::ostringstream OS;
   OS << "\nError running tool:\n ";