mpfr: use the native libraries and the right headers of gmp at toolchain stage

base/mpfr/mpfr.conf

@@ -2,7 +2,7 @@
 # This copyright note is auto-generated by ./scripts/Create-CopyPatch.
 #
 # Filename: package/.../mpfr/mpfr.conf
-# Copyright (C) 2006 The OpenSDE Project
+# Copyright (C) 2006 - 2009 The OpenSDE Project
 #
 # More information can be found in the files COPYING and README.
 #
@@ -23,3 +23,7 @@
 cumulative_patch=$(match_source_file -p 'patch')
 var_append patchfiles ' ' "$cumulative_patch"
 
+if atstage toolchain; then
+	var_append extraconfopt ' ' '--with-gmp-include=$root/$includedir'
+	var_append extraconfopt ' ' '--with-gmp-lib=$root/$libdir'
+fi