internal/zstd: avoid panic when windowSize is negative
This change fixes an edge case in the zstd decompressor where
an int conversion could result in a negative window size.
Fixes #63979
For #62513
Change-Id: Ie714bf8fb51fa509b310deb8bd2c96bd87b52852
GitHub-Last-Rev:
ab0be6578247da896f16d85e102b81994b8ee5c4
GitHub-Pull-Request: golang/go#63980
Reviewed-on: https://go-review.googlesource.com/c/go/+/540415
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: M Zhuo <mengzhuo1203@gmail.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: M Zhuo <mengzhuo1203@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>