Search for llvm-symbolizer binary in the same directory as argv[0], before

looking for it along $PATH. This allows installs of LLVM tools outside of
$PATH to find the symbolizer and produce pretty backtraces if they crash.

llvm-svn: 272232

llvm/tools/llvm-cxxdump/llvm-cxxdump.cpp

@@ -525,7 +525,7 @@ static void dumpInput(StringRef File) {
 }
 
 int main(int argc, const char *argv[]) {
-  sys::PrintStackTraceOnErrorSignal();
+  sys::PrintStackTraceOnErrorSignal(argv[0]);
   PrettyStackTraceProgram X(argc, argv);
   llvm_shutdown_obj Y;