Check if C++ compiler is present.


git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@37 632fc199-4ca6-4c93-a231-07263d6284db
diff --git a/configure.ac b/configure.ac
index 8c23a50..0245458 100644
--- a/configure.ac
+++ b/configure.ac
@@ -14,6 +14,7 @@
 # Checks for programs.
 AC_PROG_CPP
 AC_PROG_CC
+AC_PROG_CXX
 AC_PROG_INSTALL
 AC_PROG_LIBTOOL
 AC_PROG_LN_S