We have 3 different enums all expressing severity (info, warning,
error). Remove all uses with a new Severity enum in lldb-enumerations.h.

The `total` parameter for the constructor for Progress was changed to a
std::optional in https://github.com/llvm/llvm-project/pull/77547. It was originally set to 1 to indicate non-determinisitic progress, but this commit changes this. First, `UINT64_MAX` will again be used for non-deterministic progress, and `Progress` now has a static variable set to this value so that we can use this instead of a magic number. 

The member variable `m_total` could be changed to a std::optional as
well, but this means that the `ProgressEventData::GetTotal()` (which is
used for the public API) would
either need to return a std::optional value or it would return some
specific integer to represent non-deterministic progress if `m_total` is
std::nullopt.

There's no reason these strings need to be in the ConstString
StringPool, they're already string literals with static lifetime.

I plan on addressing other similar functions in follow up commits.

Differential Revision: https://reviews.llvm.org/D147833

Consider the following example as motivation. Say you have to load
symbols for 3 dynamic libraries: `libFoo`, `libBar` and `libBaz`.
Currently, there are two ways to report process for this operation:

 1. As 3 separate progress instances. In this case you create a progress
    instance with the message "Loading symbols: libFoo", "Loading
    symbols: libBar", and "Loading symbols: libBaz" respectively. Each
    progress event gets a unique ID and therefore cannot be correlated
    by the consumer.

 2. As 1 progress instance with 3 units of work. The title would be
    "Loading symbols" and you call Progress::Increment for each of the
    libraries. The 3 progress events share the same ID and can easily be
    correlated, however, in the current design, there's no way to
    include the name of the libraries.

The second approach is preferred when the amount of work is known in
advance, because determinate progress can be reported (i.e. x out of y
operations completed). An additional benefit is that the progress
consumer can decide to ignore certain progress updates by their ID if
they are deemed to noisy, which isn't trivial for the first approach due
to the use of different progress IDs.

This patch adds the ability to add a message (detail) to a progress
event update. For the example described above, progress can now be
displayed as shown:

  [1/3] Loading symbols: libFoo
  [2/3] Loading symbols: libBar
  [3/3] Loading symbols: libBaz

Differential revision: https://reviews.llvm.org/D143690

This is a preparatory patch to add an SB API to get the progress data as
SBStructuredData. The advantage of using SBStructuredData is that the
dictionary can grow over time with more fields.

This approach is identical to the way this is implemented for diagnostic
events.

Differential revision: https://reviews.llvm.org/D143687

Hoist the code that creates a StructuredData dictionary from a
diagnostic event into the DiagnosticEventData. This addresses Ismail's
code review feedback from D143687.

Differential revision: https://reviews.llvm.org/D143694

Connect the diagnostic events with the diagnostic infrastructure.

 - Emit existing diagnostic events (warnings and errors) to the
   diagnostic log.
 - Introduce a new diagnostic event (info) that's used exclusively for
   diagnostic logging and does not get broadcast.

Differential revision: https://reviews.llvm.org/D136648

On macOS, LLDB uses the DebugSymbols.framework to locate symbol rich
dSYM bundles. [1] The framework uses a variety of methods, one of them
calling into a binary or shell script to locate (and download) dSYMs.
Internally at Apple, that tool is called dsymForUUID and for simplicity
I'm just going to refer to it that way here too, even though it can be
be an arbitrary executable.

The most common use case for dsymForUUID is to fetch symbols from the
network. This can take a long time, and because the calls to the
DebugSymbols.framework are blocking, it takes a while to launch the
process. This is expected and therefore many people don't use this
functionality, but instead use add-dsym when they want symbols for a
given frame, backtrace or module. This is a little faster because you're
only fetching symbols for the module you care about, but it's still a
slow, blocking operation.

This patch introduces a hybrid approach between the two. When
symbols.enable-background-lookup is enabled, lldb will do the equivalent
of add-dsym in the background for every module that shows up in the
backtrace but doesn't have symbols for. From the user's perspective
there is no slowdown, because the process launches immediately, with
whatever symbols are available. Meanwhile, more symbol information is
added over time as the background fetching completes.

[1] https://lldb.llvm.org/use/symbols.html

rdar://76241471

Differential revision: https://reviews.llvm.org/D131328

Print diagnostic prefixes (error, warning) in their respective colors
when colors are enabled.

This silences warnings like this:

lldb/source/Core/DebuggerEvents.cpp: In member function ‘llvm::StringRef lldb_private::DiagnosticEventData::GetPrefix() const’:
lldb/source/Core/DebuggerEvents.cpp:55:1: warning: control reaches end of non-void function [-Wreturn-type]
   55 | }

Differential Revision: https://reviews.llvm.org/D123203