Regenerate again.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149569 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/configure b/configure
index 82aa6ad..2529338 100755
--- a/configure
+++ b/configure
@@ -5535,7 +5535,7 @@
 fi
 
 case "$withval" in
-  -) clang_src_root="$ac_pwd/tools/clang" ;;
+  -) clang_src_root="" ;;
   /* | [A-Za-z]:[\\/]*) clang_src_root="$withval" ;;
   *) clang_src_root="$ac_pwd/$withval" ;;
 esac
@@ -21095,6 +21095,9 @@
 ac_config_files="$ac_config_files docs/doxygen.cfg"
 
 
+if test ${clang_src_root} = ""; then
+  clang_src_root="$ac_pwd/tools/clang"
+fi
 if test -f ${clang_src_root}/README.txt; then
   ac_config_headers="$ac_config_headers ${clang_src_root}/include/clang/Config/config.h"