tool/slabratetop: add definition of freelist_aba_t

With recent kernel containing the commit 6801be4f2653 ("slub: Replace
cmpxchg_double()"), slabratetop fails to compiles with the following
error:

In file included from /virtual/main.c:86:
include/linux/slub_def.h:56:3: error: unknown type name 'freelist_aba_t'
                freelist_aba_t freelist_tid;
                ^
2 warnings and 1 error generated.
Traceback (most recent call last):
  File "/usr/share/bcc/tools/slabratetop", line 187, in <module>
    b = BPF(text=bpf_text)
        ^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/site-packages/bcc/__init__.py", line 479, in __init__
    raise Exception("Failed to compile BPF module %s" % (src_file or "<text>"))
Exception: Failed to compile BPF module <text>

Adding the definition of freelist_aba_t fixes the issue.

tools/slabratetop.py

@@ -141,6 +141,20 @@
  return NULL;
 }
 
+#ifdef CONFIG_64BIT
+typedef __uint128_t freelist_full_t;
+#else
+typedef u64 freelist_full_t;
+#endif
+
+typedef union {
+ struct {
+ void *freelist;
+ unsigned long counter;
+ };
+ freelist_full_t full;
+} freelist_aba_t;
+
 #ifdef CONFIG_SLUB
 #include <linux/slub_def.h>
 #else