gdb/

	gdb/
	* value.h (value_contents_copy, value_contents_copy_raw): Declare.
	* value.c (value_contents_copy_raw, value_contents_copy): New
	functions.
	(value_primitive_field): Use value_contents_copy_raw instead of
	memcpy.
	* valops.c (value_fetch_lazy): Use value_contents_copy instead of
	memcpy.
	(value_array, value_slice): Ditto.
	* valarith.c (value_subscripted_rvalue): Use
	value_contents_copy_raw instead of memcpy.

	gdb/testsuite/
	* gdb.trace/unavailable.exp (gdb_collect_globals_test): Add new
	tests for building arrays from unavailable values, subscripting
	non-memory rvalue unvailable arrays, and accessing fields or
	baseclasses of non-lazy unavailable values,
	* gdb.trace/unavailable.cc (small_struct, small_struct_b): New
	struct types.
	(g_smallstruct, g_smallstruct_b): New globals.