debug/macho: don't crash if dynamic symtab with no symtab
No test case because the problem can only happen for invalid data. Let
the fuzzer find cases like this.
For #47653
Fixes #58642
Change-Id: I19fee0dc9bd6239b520c15182b8f1e57bb0049bb
Reviewed-on: https://go-review.googlesource.com/c/go/+/470397 Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Bryan Mills <bcmills@google.com>