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.

Currently, lldb-server was opening the executable file to determine the
process architecture (to differentiate between 32 and 64 bit
architecture flavours). This isn't a particularly trustworthy source of
information (the file could have been changed since the process was
started) and it is not always available (file could be deleted or
otherwise inaccessible).

Unfortunately, ptrace does not give us a direct API to access the
process architecture, but we can still infer it via some of its
responses -- given that the general purpose register set of 64-bit
applications is larger [citation needed] than the GPR set of 32-bit
ones, we can just ask for the application GPR set and check its size.

This is what this patch does.

Differential Revision: https://reviews.llvm.org/D130985

Fixes PR56280.

The addition of the dummy constructors requires matching changes in os-
and arch-specific files, which I forgot about.

to NativeThreadLinux. This avoid casts down the line.

Differential Revision: https://reviews.llvm.org/D90119

Summary:
A *.cpp file header in LLDB (and in LLDB) should like this:
```
//===-- TestUtilities.cpp -------------------------------------------------===//
```
However in LLDB most of our source files have arbitrary changes to this format and
these changes are spreading through LLDB as folks usually just use the existing
source files as templates for their new files (most notably the unnecessary
editor language indicator `-*- C++ -*-` is spreading and in every review
someone is pointing out that this is wrong, resulting in people pointing out that this
is done in the same way in other files).

This patch removes most of these inconsistencies including the editor language indicators,
all the different missing/additional '-' characters, files that center the file name, missing
trailing `===//` (mostly caused by clang-format breaking the line).

Reviewers: aprantl, espindola, jfb, shafik, JDevlieghere

Reviewed By: JDevlieghere

Subscribers: dexonsmith, wuzish, emaste, sdardis, nemanjai, kbarton, MaskRay, atanasyan, arphaman, jfb, abidh, jsji, JDevlieghere, usaxena95, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D73258

Summary:
This patch follows the spirit of D63594, and removes some null checks
for things which should be operating invariants. Specifically
{Read,Write}[GF]PR now no longer check whether the supplied buffers are
null, because they never are. After this, the Do*** versions of these
function no longer serve any purpose and are inlined into their callers.

Other cleanups are possible here too, but I am taking this one step at a
time because this involves a lot of architecture-specific code, which I
don't have the hardware to test on (I did do a build-test though).

Reviewers: mgorny, jankratochvil, omjavaid, alexandreyy, uweigand

Subscribers: nemanjai, javed.absar, kbarton, lldb-commits

Differential Revision: https://reviews.llvm.org/D66744

llvm-svn: 370653

Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

Differential revision: https://reviews.llvm.org/D66259

llvm-svn: 368933