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

cmd/zpool/zpool_main.c

@@ -1760,17 +1760,19 @@ zpool_do_create(int argc, char **argv)
 			    "feature@%s", feat->fi_uname);
 
 			if (!nvlist_lookup_string(props, propname, &propval)) {
-				if (strcmp(propval, ZFS_FEATURE_DISABLED) == 0)
+				if (strcmp(propval,
+				    ZFS_FEATURE_DISABLED) == 0) {
 					(void) nvlist_remove_all(props,
 					    propname);
-				if (strcmp(propval,
+				} else if (strcmp(propval,
 				    ZFS_FEATURE_ENABLED) == 0 &&
-				    !requested_features[i])
+				    !requested_features[i]) {
 					(void) fprintf(stderr, gettext(
 					    "Warning: feature \"%s\" enabled "
 					    "but is not in specified "
 					    "'compatibility' feature set.\n"),
 					    feat->fi_uname);
+				}
 			} else if (
 			    enable_pool_features &&
 			    feat->fi_zfs_mod_supported &&
@@ -9210,7 +9212,7 @@ zpool_do_upgrade(int argc, char **argv)
 		}
 	}
 
-	(void) printf(gettext("This system supports ZFS pool feature "
+	(void) printf("%s", gettext("This system supports ZFS pool feature "
 	    "flags.\n\n"));
 	if (showversions) {
 		int i;