The function Unique_Name did not actually compute a unique name for
enumeration literals, because the type to which the literal belongs was not
taken into account. This patch fixes the issue.

Tested on x86_64-pc-linux-gnu, committed on trunk

2011-09-02  Johannes Kanig  <kanig@adacore.com>

	* sem_util.adb (Unique_Name): To obtain a unique name for enumeration
	literals, take into account the type name; the type is *not*
	the scope for an enumeration literal.