qemu/atomic: Add aligned_{int64,uint64}_t types

Use it to avoid some clang-12 -Watomic-alignment errors,
forcing some structures to be aligned and as a pointer when
we have ensured that the address is aligned.

Tested-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

util/qsp.c

@@ -83,8 +83,8 @@ typedef struct QSPCallSite QSPCallSite;
 struct QSPEntry {
     void *thread_ptr;
     const QSPCallSite *callsite;
-    uint64_t n_acqs;
-    uint64_t ns;
+    aligned_uint64_t n_acqs;
+    aligned_uint64_t ns;
     unsigned int n_objs; /* count of coalesced objs; only used for reporting */
 };
 typedef struct QSPEntry QSPEntry;