autoconf: put generated clang files in build dir

It was writing generated files to the clang srcdir when
'--with-clang-srcdir' was specified.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149756 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/configure b/configure
index 0c16638..7acea4e 100755
--- a/configure
+++ b/configure
@@ -21055,9 +21055,11 @@
   clang_src_root="$srcdir/tools/clang"
 fi
 if test -f ${clang_src_root}/README.txt; then
-  ac_config_headers="$ac_config_headers ${clang_src_root}/include/clang/Config/config.h"
+    configh="include/clang/Config/config.h"
+  doxy="docs/doxygen.cfg"
+  ac_config_headers="$ac_config_headers tools/clang/${configh}:${clang_src_root}/${configh}.in"
 
-  ac_config_files="$ac_config_files ${clang_src_root}/docs/doxygen.cfg"
+  ac_config_files="$ac_config_files tools/clang/${doxy}:${clang_src_root}/${doxy}.in"
 
 fi
 
@@ -21679,8 +21681,8 @@
     "Makefile.config") CONFIG_FILES="$CONFIG_FILES Makefile.config" ;;
     "llvm.spec") CONFIG_FILES="$CONFIG_FILES llvm.spec" ;;
     "docs/doxygen.cfg") CONFIG_FILES="$CONFIG_FILES docs/doxygen.cfg" ;;
-    "${clang_src_root}/include/clang/Config/config.h") CONFIG_HEADERS="$CONFIG_HEADERS ${clang_src_root}/include/clang/Config/config.h" ;;
-    "${clang_src_root}/docs/doxygen.cfg") CONFIG_FILES="$CONFIG_FILES ${clang_src_root}/docs/doxygen.cfg" ;;
+    "tools/clang/${configh}") CONFIG_HEADERS="$CONFIG_HEADERS tools/clang/${configh}:${clang_src_root}/${configh}.in" ;;
+    "tools/clang/${doxy}") CONFIG_FILES="$CONFIG_FILES tools/clang/${doxy}:${clang_src_root}/${doxy}.in" ;;
     "bindings/ocaml/llvm/META.llvm") CONFIG_FILES="$CONFIG_FILES bindings/ocaml/llvm/META.llvm" ;;
     "setup") CONFIG_COMMANDS="$CONFIG_COMMANDS setup" ;;
     "Makefile") CONFIG_COMMANDS="$CONFIG_COMMANDS Makefile" ;;