DWARF: fix scoping for descriptions of local types

DWARF: fix scoping for descriptions of local types

In Ada, it is possible to have nested subprograms in the following
configuration:

    procedure Parent is
       type T;
       [...]
       procedure Child (Value : T) is
       begin
          [...]
       end Child;
    begin
       [...]
    end Parent;

As we currently generate debugging information for Child first before
Parent, the debug info for T appears in global scope since the DIE for
Parent does not exist yet.

This patch makes sure that when we generate early debug info for a
nested function, we trigger generation for the parent function first.

gcc/

	* dwarf2out.c (dwarf2out_early_global_decl): For nested
	functions, call dwarf2out_decl on the parent function first.

gcc/testsuite/

	* gnat.dg/debug9.adb: New testcase.

From-SVN: r241023