Add sanitizer support and clean up sanitizer findings (#9601)

- Added sanitizer support. `address`, `undefined` and `thread` sanitizers are available.  
- To build Redis with desired sanitizer : `make SANITIZER=undefined`
- There were some sanitizer findings, cleaned up codebase
- Added tests with address and undefined behavior sanitizers to daily CI.
- Added tests with address sanitizer to the per-PR CI (smoke out mem leaks sooner).

Basically, there are three types of issues : 

**1- Unaligned load/store** : Most probably, this issue may cause a crash on a platform that
does not support unaligned access. Redis does unaligned access only on supported platforms.

**2- Signed integer overflow.** Although, signed overflow issue can be problematic time to time
and change how compiler generates code, current findings mostly about signed shift or simple
addition overflow. For most platforms Redis can be compiled for, this wouldn't cause any issue
as far as I can tell (checked generated code on godbolt.org).

 **3 -Minor leak** (redis-cli), **use-after-free**(just before calling exit());

UB means nothing guaranteed and risky to reason about program behavior but I don't think any
of the fixes here worth backporting. As sanitizers are now part of the CI, preventing new issues
will be the real benefit. 

1 files changed, 1 insertions, 0 deletions

diff --git a/src/hyperloglog.c b/src/hyperloglog.c
index 3620d2d4a..82c43d44c 100644
--- a/src/hyperloglog.c
+++ b/src/hyperloglog.c
@@ -393,6 +393,7 @@ static char *invalid_hll_err = "-INVALIDOBJ Corrupted HLL object detected";
 /* Our hash function is MurmurHash2, 64 bit version.
  * It was modified for Redis in order to provide the same result in
  * big and little endian archs (endian neutral). */
+REDIS_NO_SANITIZE("alignment")
 uint64_t MurmurHash64A (const void * key, int len, unsigned int seed) {
     const uint64_t m = 0xc6a4a7935bd1e995;
     const int r = 47;