AArch64 AAPCS: Ignore static members

AArch64 AAPCS: Ignore static members

Static members in C++ structs are global data and therefore not part of the
list of struct members considered for passing in registers.

Note the corresponding code in GCC (from which the GDB AAPCS code is based)
does not have any static member checks due to the static members not being
part of the struct type at that point.

Extend gdb.base/infcall-nested-structs.exp to test structs with static
members when compiled for C++.  XFAIL more cases for x86_64 (see gdb/24104).
For completeness, ensure some test cases have both empty structures and
static members.

Also fixes gdb.dwarf2/dw2-cp-infcall-ref-static.exp.

gdb/ChangeLog:

	* aarch64-tdep.c (aapcs_is_vfp_call_or_return_candidate_1): Check
	for static members.
	(pass_in_v_vfp_candidate): Likewise.

gdb/testsuite/ChangeLog:

	* gdb.base/infcall-nested-structs.c (struct struct_static_02_01):
	New structure.
	(struct struct_static_02_02): Likewise.
	(struct struct_static_02_03): Likewise.
	(struct struct_static_02_04): Likewise.
	(struct struct_static_04_01): Likewise.
	(struct struct_static_04_02): Likewise.
	(struct struct_static_04_03): Likewise.
	(struct struct_static_04_04): Likewise.
	(struct struct_static_06_01): Likewise.
	(struct struct_static_06_02): Likewise.
	(struct struct_static_06_03): Likewise.
	(struct struct_static_06_04): Likewise.
	(cmp_struct_static_02_01): Likewise.
	(cmp_struct_static_02_02): Likewise.
	(cmp_struct_static_02_03): Likewise.
	(cmp_struct_static_02_04): Likewise.
	(cmp_struct_static_04_01): Likewise.
	(cmp_struct_static_04_02): Likewise.
	(cmp_struct_static_04_03): Likewise.
	(cmp_struct_static_04_04): Likewise.
	(cmp_struct_static_06_01): Likewise.
	(cmp_struct_static_06_02): Likewise.
	(cmp_struct_static_06_03): Likewise.
	(cmp_struct_static_06_04): Likewise.
	(call_all): Test new structs.
	* gdb.base/infcall-nested-structs.exp: Likewise.