When retrieving the location of the function declaration, we were
dropping the file component on the floor, which resulted in an amusingly
confusing situation were we displayed the file containing the
implementation of the function, but used the line number of the
declaration. This patch fixes that.

It required a small refactor Function::GetStartLineSourceLineInfo to
return a SupportFile (instead of just the file spec), which in turn
necessitated changes in a couple of other places as well.

This patch removes all of the Set.* methods from Status.

This cleanup is part of a series of patches that make it harder use the
anti-pattern of keeping a long-lives Status object around and updating
it while dropping any errors it contains on the floor.

This patch is largely NFC, the more interesting next steps this enables
is to:
1. remove Status.Clear()
2. assert that Status::operator=() never overwrites an error
3. remove Status::operator=()

Note that step (2) will bring 90% of the benefits for users, and step
(3) will dramatically clean up the error handling code in various
places. In the end my goal is to convert all APIs that are of the form

`    ResultTy DoFoo(Status& error)
`
to

`    llvm::Expected<ResultTy> DoFoo()
`
How to read this patch?

The interesting changes are in Status.h and Status.cpp, all other
changes are mostly

` perl -pi -e 's/\.SetErrorString/ = Status::FromErrorString/g' $(git
grep -l SetErrorString lldb/source)
`
plus the occasional manual cleanup.

Improve the chance of resolving file/line breakpoints by realpath'ing the support files before doing a second match attempt, with some conditions applied.

A working [hello-world example](https://github.com/royitaqi/lldb_demos/blob/main/realpath/README.md).

See [patch](https://github.com/llvm/llvm-project/pull/102223) for more info about problem/motivation, details of the feature, new settings, telemetries and tests.

The TestBreakpointCommand test is incorrectly disabled for Windows
target. We can disable it for Windows host instead or just fix the
issue. This patch fixes the path separator in
BreakpointResolverFileLine::DeduceSourceMapping() and the Windows
specific absolute path in the test in case of the Windows host.

This is another step towards supporting DWARF5 checksums and inline
source code in LLDB. This is a reland of #85468 but without the
functional change of storing the support file from the line table (yet).

Reverts llvm/llvm-project#85468 because @slackito reports this broke
stepping in one of their tests [1] and this patch was meant to be NFC.

[1]
https://github.com/llvm/llvm-project/commit/d5a277d309e92b1d3e493da6036cffdf815105b1#commitcomment-139991120

This is another step towards supporting DWARF5 checksums and inline
source code in LLDB.

This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.

I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.

These appear to be unused.

BreakpointResolver::CreateFromStructuredData returns a
BreakpointResolverSP, but all of the subclasses return raw pointers.
Instead of creating a raw pointer and shoving it into a shared pointer,
it seems reasonable to just create the shared pointer directly.