Generate debug info for local dynamic record types

In Ada you can embed VLAs in local record types and thus end up with
dynamic offsets in record types, which are not well described in DWARF
because 1) the temporaries generated for them by the gimplifier are
naturally marked DECL_IGNORED_P and 2) when the types are referenced
in nested subprograms, the DWARF back-end does not correctly handle
the rewritten references.

gcc/
	* dwarf2out.c (loc_list_from_tree_1) <DECL>: During early DWARF, do
	not expand the VALUE_EXPR of variables put in the non-local frame.
	* gimplify.c (gimplify_type_sizes) <RECORD_TYPE>: If the type is not
	to be ignored for debug info, ensure its variable offsets are not.
gcc/testsuite/
	* gnat.dg/debug8.adb: Minor tweak.
	* gnat.dg/debug11.adb: Likewise.
	* gnat.dg/debug16.adb: Likewise.
	* gnat.dg/debug17.adb: New test.
	* gnat.dg/specs/debug1.ads: Minor tweak.