debug/dwarf: don't crash on negative range/rnglist offset
debug/dwarf: don't crash on negative range/rnglist offset

No test case because the problem can only happen for invalid data. Let
the fuzzer find cases like this.

Fixes #55948

Change-Id: I7ba40ba928d2a14d4ac5b39f966173f3868d4729
Reviewed-on: https://go-review.googlesource.com/c/go/+/436876
TryBot-Result: Gopher Robot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Dmitri Shuralyov <d181b7fea0ec87c86ba5a890ab716db52498e3ba@google.com>
Auto-Submit: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@google.com>
Run-TryBot: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
Reviewed-by: Tobias Klauser <0a68dd4915066ec5d3f81f75a828fee53dcc8822@gmail.com>
Reviewed-by: Than McIntosh <4b2922593166fc595a9b1a408f34f5d3817fe9d2@google.com>

golang/go,golang/go,golang/go,golang/go,golang/go,golang/go,golang/go,golang/go