Add --enable-asan and --enable-ubsan switches

`configure` now accepts `--enable-asan` and `--enable-ubsan` switches
which results in passing `-fsanitize=address`
and `-fsanitize=undefined`, respectively, to the compiler. Those
flags are enabled in GitHub workflows for ZTS and zloop. Errors
reported by both instrumentations are corrected, except for:

- Memory leak reporting is (temporarily) suppressed. The cost of
  fixing them is relatively high compared to the gains.

- Checksum computing functions in `module/zcommon/zfs_fletcher*`
  have UBSan errors suppressed. It is completely impractical
  to enforce 64-byte payload alignment there due to performance
  impact.

- There's no ASan heap poisoning in `module/zstd/lib/zstd.c`. A custom
  memory allocator is used there rendering that measure
  unfeasible.

- Memory leaks detection has to be suppressed for `cmd/zvol_id`.
  `zvol_id` is run by udev with the help of `ptrace(2)`. Tracing is
  incompatible with memory leaks detection.

Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: szubersk <szuberskidamian@gmail.com>
Closes #12928

include/zfs_fletcher.h

@@ -160,4 +160,20 @@ _ZFS_FLETCHER_H const fletcher_4_ops_t fletcher_4_aarch64_neon_ops;
 }
 #endif
 
+#if	defined(ZFS_UBSAN_ENABLED)
+#if	defined(__has_attribute)
+#if	__has_attribute(no_sanitize_undefined)
+#define	ZFS_NO_SANITIZE_UNDEFINED __attribute__((no_sanitize_undefined))
+#elif	__has_attribute(no_sanitize)
+#define	ZFS_NO_SANITIZE_UNDEFINED __attribute__((no_sanitize("undefined")))
+#else
+#error	"Compiler has to support attribute "
+	"`no_sanitize_undefined` or `no_sanitize(\"undefined\")`"
+	"when compiling with UBSan enabled"
+#endif	/* __has_attribute(no_sanitize_undefined) */
+#endif	/* defined(__has_attribute) */
+#else
+#define	ZFS_NO_SANITIZE_UNDEFINED
+#endif	/* defined(ZFS_UBSAN_ENABLED) */
+
 #endif	/* _ZFS_FLETCHER_H */