Add some autoconf checks recommended by autoscan.

configure.ac

@@ -48,8 +48,24 @@ PKG_CHECK_VAR([LIBVARNISHAPI_LIBDIR], [varnishapi], [libdir])
 AC_SUBST([VARNISH_LIBRARY_PATH],
 	[$LIBVARNISHAPI_LIBDIR:$LIBVARNISHAPI_LIBDIR/varnish])
 
-# Checks for C sources
-# AC_CHECK_FUNCS([strdup])
+# Checks for C functions
+AC_CHECK_FUNCS([memset])
+AC_CHECK_FUNCS([strchr])
+
+# C headers
+AC_CHECK_HEADERS([limits.h])
+AC_CHECK_HEADERS([stddef.h])
+AC_CHECK_HEADER_STDBOOL
+
+# C types
+AC_TYPE_SIZE_T
+AC_TYPE_SSIZE_T
+AC_TYPE_UINT8_T
+AC_TYPE_UINT16_T
+AC_TYPE_UINT32_T
+AC_TYPE_UINT64_T
+
+AC_C_INLINE
 
 AC_ARG_VAR([VARNISHSRC], [path to Varnish source tree (REQUIRED)])
 if test "${VARNISHSRC+set}" != set; then