The LLVM Coding Standards [1] specify that:
> [T]o match error message styles commonly produced by other tools,
> start the first sentence with a lowercase letter, and finish the last
> sentence without a period, if it would end in one otherwise.
Historically, that hasn't been something we've enforced in LLDB, but in
the past year or so I've started to pay more attention to this in code
reviews. This PR brings more error messages in compliance, further
increasing consistency.
I also adopted `createStringErrorV` where it improved the code as a
drive-by for lines I was already touching.
[1] https://llvm.org/docs/CodingStandards.html#error-and-warning-messages
Assisted-by: Claude Code
Synthetic providers for collection types use a child name format of
"[N]".
This `ValueObjectSynthetic` to automatically convert child names in this
convention to the index embedded in the subscript string. With this
change, synthetic formatters for collections will only need to implement
`GetIndexOfChildWithName` or `get_child_index` for non-indexed
collection children. Some examples of non-indexed children are
`$$dereference$$` support, or "hidden" children.
The automatic conversion applies to N values that are less than the
number of children reported by the synthetic provider.
Vector registers have synthetic values for display purposes. This causes
SBValue::GetExpressionPath to dispatch
to ValueObjectSynthetic instead of ValueObjectRegister, producing
incorrect results.
Fixes#147144
