[PATCH,v2] [sim] Fix build failure in d10v sim

[Luis Machado via Gdb-patches <gdb-patches@sourceware.org>]

While building all targets on Ubuntu 20.04/aarch64, I ran into the following
build error:

In file included from /usr/include/string.h:495,
                 from ../../bfd/bfd.h:48,
                 from ../../../../repos/binutils-gdb/sim/d10v/interp.c:4:
In function 'memset',
    inlined from 'sim_create_inferior' at ../../../../repos/binutils-gdb/sim/d10v/interp.c:1146:3:
/usr/include/aarch64-linux-gnu/bits/string_fortified.h:71:10: error: ‘__builtin_memset’ offset [33, 616] from the object at ‘State’ is out of the bounds of referenced subobject ‘regs’ with type ‘reg_t[16]’ {aka ‘short unsigned int[16]’} at offset 0 [-Werror=array-bounds]
   71 |   return __builtin___memset_chk (__dest, __ch, __len, __bos0 (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make[3]: *** [Makefile:558: interp.o] Error 1

The following patch fixes this for me.

OK?

sim/ChangeLog:

YYYY-MM-DD  Luis Machado  <luis.machado@linaro.org>

	d10v/interp.c (sim_create_inferior): Fix memset call.
---
 sim/d10v/interp.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/sim/d10v/interp.c b/sim/d10v/interp.c
index 86e566a79fb..64dd392381c 100644
--- a/sim/d10v/interp.c
+++ b/sim/d10v/interp.c
@@ -1142,8 +1142,12 @@ sim_create_inferior (SIM_DESC sd, struct bfd *abfd,
 {
   bfd_vma start_address;
 
-  /* reset all state information */
-  memset (&State.regs, 0, (uintptr_t)&State.mem - (uintptr_t)&State.regs);
+  /* Make sure we have the right structure for the following memset.  */
+  _Static_assert ((uintptr_t) &State == (uintptr_t) &State.regs,
+		  "&State != &State.regs");
+
+  /* Reset state from the regs field until the mem field.  */
+  memset (&State, 0, (uintptr_t)&State.mem - (uintptr_t)&State.regs);
 
   /* There was a hack here to copy the values of argc and argv into r0
      and r1.  The values were also saved into some high memory that
-- 
2.25.1