Error on multiline basic string backslash trimming with CRLF

[moorereason]

Describe the bug
go-toml returns an error on a multiline basic string with an unescaped backslash followed by CRLF. This sequence should be valid.

To Reproduce
https://go.dev/play/p/3aIPpYSTpxO

toml.Unmarshal([]byte("0=\"\"\"\\\r\n\"\"\""), &v)

Expected behavior
I expect the parser to recognize the \r\n sequence as a whitespace character to be trimmed. The TOML spec:

For writing long strings without introducing extraneous whitespace, use a "line ending backslash". When the last non-whitespace character on a line is an unescaped \, it will be trimmed along with all whitespace (including newlines) up to the next non-whitespace character or closing delimiter.

Versions

• go-toml: 5cbdea6
• go version go1.17.5 linux/amd64

Additional context
Also submitted a PR to toml-test to include this case: toml-lang/toml-test#105

Found while doing differential fuzzing against toml.dart. 🎯

[pelletier]

Should be fixed in 177b4a5. Thank you!