[Ada] Fix expansion of blocks in loops inside elaboration code

[Ada] Fix expansion of blocks in loops inside elaboration code

2018-07-16  Ed Schonberg  <schonberg@adacore.com>

gcc/ada/

	* exp_ch7.adb (Check_Unnesting_Elaboration_Code): Handle loops that
	contain blocks in the elaboration code for a package body. Create the
	elaboration subprogram wrapper only if there is a subprogram
	declaration in a block or loop.

From-SVN: r262728