ari, btrace: avoid unsigned long long

ari, btrace: avoid unsigned long long

Fix the ARI warning about the use of unsigned long long.  We can't use
ULONGEST as this is defined unsigned long on 64-bit systems.  This will
result in a compile error when storing a pointer to an unsigned long long
structure field (declared in perf_event.h as __u64) in a ULONGEST * variable.

Use size_t to hold the buffer size inside GDB and __u64 when interfacing the
Linux kernel.

gdb/
	* nat/linux-btrace.c (perf_event_read): Change the type of DATA_HEAD.
	(perf_event_read_all): Change the type of SIZE and DATA_HEAD.
	(perf_event_read_bts): Change the type of SIZE and READ.
	(linux_enable_bts): Change the type of SIZE, PAGES, DATA_SIZE,
	and DATA_OFFSET.  Move DATA_SIZE declaration.  Restrict the buffer size
	to UINT_MAX.  Check for overflows when using DATA_HEAD from the perf
	mmap page.
	(linux_enable_pt): Change the type of PAGES and SIZE.  Restrict the
	buffer size to UINT_MAX.
	(linux_read_bts): Change the type of BUFFER_SIZE, SIZE, DATA_HEAD, and
	DATA_TAIL.
	* nat/linux-btrace.h (struct perf_event_buffer)<size, data_head>
	<last_head>: Change type.
	* common/btrace-common.h (struct btrace_dat_pt) <size>: Change type.
	* common/btrace-common.c (btrace_data_append): Change the type of
	SIZE.
	* btrace.c (parse_xml_raw): Change the type of SIZE.  Change oddness
	check.