ada: Bad internal naming when using pragma Compile_Time_Error

ada: Bad internal naming when using pragma Compile_Time_Error

This patch fixes an error in the compiler whereby the presence of a condition
which tests the size of a type not known at compile time within an instance
of pragma Compile_Time_Error causes incorrect internal names to be generated
for said type during expansion.

gcc/ada/

	* sem_prag.adb (Defer_Compile_Time_Warning_Error_To_BE): Better
	handle itypes such that the tree copy required for the expansion
	of the pragma doesn't cause ordering problems with internal names.