PR145731 corrected the analyzer test runner to consider use of z3 when
used by testcases, which exposed problems in test cases PR37855.c and
crashes in z3-crosscheck.c This change fixes those crashes and
re-enables the test cases that were "XFAIL"'d out.

Co-authored-by: einvbri <vince.a.bridgers@ericsson.com>

This patch fixes the following error:
```
llvm/lib/Support/TextEncoding.cpp:274:11: error: cannot initialize a variable of type 'char *' with an rvalue of type 'const char *'
  274 |     char *Input = InputLength ? const_cast<char *>(Source.data()) : "";
      |           ^       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```

This patch is part of a series that adds origin-tracking to the debugify
source location coverage checks, allowing us to report symbolized stack
traces of the point where missing source locations appear.

This patch adds a pair of new functions in `signals.h` that can be used
to collect and symbolize stack traces respectively. This has major
implementation overlap with the existing stack trace
collection/symbolizing methods, but the existing functions are
specialized for dumping a stack trace to stderr when LLVM crashes, while
these new functions are meant to be called repeatedly during the
execution of the program, and therefore we need a separate set of
functions.

Assume that mingw builds are made with mingw-w64 headers.

The old mingw.org distribution isn't even accessible at the moment, and
their project hosting site (osdn.net) seems to have been down for a
couple of years, and their old project hosting (at sourceforge.net)
hasn't been updated since 2018.

Cygwin environment has pthread functionality but LLVM integration
doesn't care it nor provide fallback.
Using Linux integration for Cygwin works fine.

mingw-w64 has had the _HEAPOK define since the initial commits in 2007;
unclear when/where it was added for mingw.org headers, but it does seem
to exist there as well (at least in versions from 2011).

This workaround stems from 53fbecce6e8b7d1f024e3dc6df4160fe9a577ff1 from
2004 - it is no longer relevant today.

## Purpose
This patch ensures that the BLAKE3 implementation in the LLVM Support
library exports its public interface with `__declspec(dllexport)` when
building LLVM as a Windows DLL.

## Background
The effort to support building LLVM as a Windows DLL is tracked in
#109483. Additional context is provided in [this
discourse](https://discourse.llvm.org/t/psa-annotating-llvm-public-interface/85307).

## Overview
Replicate [this
logic](https://github.com/llvm/llvm-project/blob/main/llvm/cmake/modules/AddLLVM.cmake#L662-L664)
from `llvm_add_library()` for the `LLVMSupportBlake3` target. Without
this change, the `llvm_blake_` functions will only be annotated with
`__declspec(dllimport)` when building LLVM as a Windows DLL which leads
to inconsistent DLL linkage warnings from MSVC and `clang-cl`.

#143514 broke the `clang-solaris11-sparcv9` bot; from what I can tell
that’s Solaris and according to `SolarisTargetInfo::getOSDefines`, the
macro `__sun__` should be defined on Solaris, so check for that and
don’t try to query the terminal size if it is defined.

Not sure this is the best solution but hopefully it fixes the bot.

On unix systems, we were trying to determine the terminal width using
the `COULMNS` environment variable. Unfortunately, `COLUMNS` is not 
exported by all shells and thus not available on some systems.

We were previously using `ioctl()` for this; fall back to doing so if `COLUMNS`
does not exist or does not store a positive integer.

This essentially reverts a3eb3d3d92d037fe3c9deaad87f6fc42fe9ea766 and
parts of https://reviews.llvm.org/D61326.

For more information, see #139499.

Fixes #139499.

This patch removes the C++
disablezOSAutoConversion,enablezOSAutoConversion declarations and also
updates Path.inc to use the common function.