[lldb] Fix logic error in AppleObjCTypeEncodingParser (#137067)

Fixes parsing of an ObjC type encoding such as `{?="a""b"}`. Parsing of such a type
encoding would lead to an assert. This was observed when running `language objc
class-table dump`.

The function `ReadQuotedString` consumes the closing quote, however one of its two
callers (`ReadStructElement`) was also consuming a quote. For the above type encoding,
where two quoted strings occur back to back, the parser would unintentionally consume
the opening quote of the second quoted string - leaving the remaining text with an
unbalanced quote.

This changes fixes `ReadStructElement` to not consume a quote after calling
`ReadQuotedString`.

For callers to know whether a string was successfully parsed, `ReadQuotedString` now
returns an optional string.

0 files changed, 0 insertions, 0 deletions