- don't hardcode libstdc++

Index: build/php.m4
--- build/php.m4.orig
+++ build/php.m4
@@ -742,7 +742,9 @@ AC_DEFUN([PHP_REQUIRE_CXX],[
   if test -z "$php_cxx_done"; then
     AC_PROG_CXX
     AC_PROG_CXXCPP
-    PHP_ADD_LIBRARY(stdc++)
+    for i in $LIBCXX; do
+      PHP_ADD_LIBRARY($i)
+    done
     php_cxx_done=yes
   fi
 ])