Change some void* to gdb_byte*

There are a bunch of places where a void* is implicitely casted into a
gdb_byte*.  The auto-insert-casts script added explicit casts at those
places.  However, in many cases, it makes more sense to just change the
void* to a gdb_byte*.

gdb/ChangeLog:

	* aarch64-tdep.c (stack_item_t): Change type of data to gdb_byte*.
	* arm-tdep.c (struct stack_item): Likewise.
	(push_stack_item): Add gdb_byte* cast.
	* avr-tdep.c (struct stack_item): Change type of data to gdb_byte*.
	(push_stack_item): Add gdb_byte* cast.
	* cli/cli-dump.c (dump_memory_to_file): Change type of buf to gdb_byte*
	and add cast.
	* cris-tdep.c (struct stack_item): Change type of data to gdb_byte*.
	(push_stack_item): Add gdb_byte* cast.
	* gcore.c (gcore_copy_callback): Change type of memhunk to gdb_byte* and
	add cast.
	* gdbtypes.h (print_scalar_formatted): Change type of first parameter to
	gdb_byte*.
	* h8300-tdep.c (h8300_extract_return_value): Change type of valbuf to
	gdb_byte* and remove unnecessary cast.
	(h8300h_extract_return_value): Likewise.
	(h8300_store_return_value): Change type of valbuf to gdb_byte*.
	(h8300h_store_return_value): Likewise.
	* iq2000-tdep.c (iq2000_extract_return_value): Change type of valbuf to
	gdb_byte* and remove unnecessary cast.
	* jit.c (jit_reader_try_read_symtab): Change type of gdb_mem to gdb_byte*
	and add cast.
	* m32r-tdep.c (m32r_store_return_value): Change type of valbuf to
	gdb_byte* and remove unnecessary cast.
	(m32r_extract_return_value): Change type of dst to gdb_byte* and remove
	valbuf.
	* mep-tdep.c (mep_pseudo_cr32_read): Change type of buf to gdb_byte*.
	(mep_pseudo_cr64_read): Likewise.
	(mep_pseudo_csr_write): Likewise.
	(mep_pseudo_cr32_write): Likewise.
	(mep_pseudo_cr64_write): Likewise.
	* mi/mi-main.c (mi_cmd_data_write_memory): Change type of buffer to
	gdb_byte* and add cast.
	* moxie-tdep.c (moxie_store_return_value): Change type of valbuf to
	gdb_byte* and remove unnecessary cast.
	(moxie_extract_return_value): Change type of dst to gdb_byte* and remove
	valbuf.
	* p-valprint.c (print_scalar_formatted): Change type of valaddr to
	gdb_byte*.
	* printcmd.c (void): Likewise.
	* python/py-inferior.c (infpy_read_memory): Change type of buffer to
	gdb_byte* and add cast.
	(infpy_write_memory): Likewise.
	(infpy_search_memory): Likewise.
	* regcache.c (regcache_raw_write_signed): Change type of buf to gdb_byte*
	and add cast.
	(regcache_raw_write_unsigned): Likewise.
	(regcache_cooked_write_signed): Likewise.
	(regcache_cooked_write_unsigned): Likewise.
	* sh64-tdep.c (h64_extract_return_value): Change type of valbuf to
	gdb_byte*.

gdb/avr-tdep.c

@@ -1198,7 +1198,7 @@ struct stack_item
 {
   int len;
   struct stack_item *prev;
-  void *data;
+  gdb_byte *data;
 };
 
 static struct stack_item *
@@ -1206,7 +1206,7 @@ push_stack_item (struct stack_item *prev, const bfd_byte *contents, int len)
 {
   struct stack_item *si;
   si = XNEW (struct stack_item);
-  si->data = xmalloc (len);
+  si->data = (gdb_byte *) xmalloc (len);
   si->len = len;
   si->prev = prev;
   memcpy (si->data, contents, len);