[Ada] Unnesting transformations for blocks in package bodies

[Ada] Unnesting transformations for blocks in package bodies

The declarations in the package body may have created blocks with nested
subprograms. Such a block must be transformed into a procedure followed
by a call to it, so that unnesting can handle uplevel references within
these nested subprograms (typically generated subprograms to handle
finalization actions).

2018-11-14  Ed Schonberg  <schonberg@adacore.com>

gcc/ada/

	* exp_ch7.adb (Check_Unnesting_In_Declarations): New procedure
	to transform blocks that appear in the declarative part of a
	package body into subprograms if they contain generated
	subprograms (such as finalization routines). Needed to generate
	the proper upward references in unnesting mode.

From-SVN: r266117