brotli: test failure on Fedora rawhide ppc64le

[rathann]

cc9eb1d with #64 applied fails brotli tests when built on Fedora rawhide ppc64le arch:

GOPATH=/builddir/build/BUILD/compress-cc9eb1d7ad760af14e8f918698f745e80377af4f/_build:/usr/share/gocode
+ go test -buildmode pie -compiler gc -ldflags '-extldflags '\''-Wl,-z,relro -Wl,--as-needed  -Wl,-z,now -specs=/usr/lib/rpm/redhat/redhat-hardened-ld '\'''
--- FAIL: TestReader (0.15s)
    reader_test.go:528: test 20, mismatching error:
        got brotli: corrupted input
        want IsCorrupted(err) == true
    reader_test.go:528: test 22, mismatching error:
        got brotli: corrupted input
        want IsCorrupted(err) == true
    reader_test.go:528: test 26, mismatching error:
        got brotli: corrupted input
        want IsCorrupted(err) == true
    reader_test.go:528: test 27, mismatching error:
        got brotli: corrupted input
        want IsCorrupted(err) == true
    reader_test.go:528: test 28, mismatching error:
        got brotli: corrupted input
        want IsCorrupted(err) == true
    reader_test.go:528: test 33, mismatching error:
        got brotli: corrupted input
        want IsCorrupted(err) == true
    reader_test.go:528: test 34, mismatching error:
        got brotli: corrupted input
        want IsCorrupted(err) == true
    reader_test.go:528: test 39, mismatching error:
        got brotli: corrupted input
        want IsCorrupted(err) == true
    reader_test.go:528: test 44, mismatching error:
        got brotli: corrupted input
        want IsCorrupted(err) == true
    reader_test.go:528: test 49, mismatching error:
        got brotli: corrupted input
        want IsCorrupted(err) == true
    reader_test.go:528: test 50, mismatching error:
        got brotli: corrupted input
        want IsCorrupted(err) == true
    reader_test.go:528: test 53, mismatching error:
        got brotli: corrupted input
        want IsCorrupted(err) == true
    reader_test.go:528: test 54, mismatching error:
        got brotli: corrupted input
        want IsCorrupted(err) == true
    reader_test.go:528: test 56, mismatching error:
        got brotli: corrupted input
        want IsCorrupted(err) == true
    reader_test.go:528: test 57, mismatching error:
        got brotli: corrupted input
        want IsCorrupted(err) == true
    reader_test.go:528: test 63, mismatching error:
        got brotli: corrupted input
        want IsCorrupted(err) == true
FAIL

Unfortunately, I don't know enough Go and I'm not familiar with brotli to fix this right now.

[dsnet]

This is a very strange error as it suggests that something with the Go type system is going wrong, perhaps caused by the Go compiler doing something odd. I'm not sure if there's anything to address from my end without more information.