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

tests/zfs-tests/include/commands.cfg

@@ -51,6 +51,7 @@ export SYSTEM_FILES_COMMON='arp
     iostat
     kill
     ksh
+    ldd
     ln
     logname
     ls

tests/zfs-tests/include/default.cfg.in

@@ -155,6 +155,21 @@ done
 
 export MAX_PARTITIONS=8
 
+if [ "@ASAN_ENABLED@" = "yes" ]; then
+	export ASAN_OPTIONS=abort_on_error=true:halt_on_error=true:allocator_may_return_null=true:disable_coredump=false:detect_stack_use_after_return=true
+
+	# TODO
+	# disable memory leaks detection
+	# there are quite many of them and they are not as
+	# destructive to CLI programs as they are to daemons
+	export ASAN_OPTIONS="$ASAN_OPTIONS:detect_leaks=false"
+fi
+
+if [ "@UBSAN_ENABLED@" = "yes" ]; then
+	export UBSAN_OPTIONS=abort_on_error=true:halt_on_error=true:print_stacktrace=true
+fi
+
+
 case $(uname -o) in
 GNU/Linux)
 	unpack_opts="--sparse -xf"