libcutils: cleanups for -fsanitize=integer

Hash functions rely on overflow behavior, so whitelist them.

ATRACE_TAG_NOT_READY: use an unsigned constant when shifting bits.
Otherwise, the value overflows on shift. The users of this constant
assign it to a uint64_t variable.

Change-Id: I21c437ce2083525e906c3ead3259ec34a1ef4b66
diff --git a/libcutils/hashmap.c b/libcutils/hashmap.c
index 65539ea..ede3b98 100644
--- a/libcutils/hashmap.c
+++ b/libcutils/hashmap.c
@@ -77,6 +77,9 @@
 /**
  * Hashes the given key.
  */
+#ifdef __clang__
+__attribute__((no_sanitize("integer")))
+#endif
 static inline int hashKey(Hashmap* map, void* key) {
     int h = map->hash(key);
 
@@ -152,6 +155,10 @@
     free(map);
 }
 
+#ifdef __clang__
+__attribute__((no_sanitize("integer")))
+#endif
+/* FIXME: relies on signed integer overflow, which is undefined behavior */
 int hashmapHash(void* key, size_t keySize) {
     int h = keySize;
     char* data = (char*) key;