Add a "fatal" log level, which kills ds2 when used.
Print the "listening" message only in lldb compat mode.

This message is useless otherwise, so get rid of it.
Add build of the fault handler to CMake.
Get rid of constexpr.

This is not supported by MSVC pre-2014.
Correct the definition of a macro

The macro was not in use previously.  A missing closing parenthesis results in
the file being unusable.
Consolidate architecture definition

Create a new definition for the architecture.  This allows us to use the same
definition irrespective of the compiler used.  MSVC defines _M_* macros, whilst
gcc and clang define __*__ macros.  Adjust the codebase to use the new ARCH_*
macros defined in Base.h.
Use __FUNCTION__ instead of __func__.

This is supported by more compilers.
Fix a typo in an architecture define in one of the earlier commits.
Rework handling of ARM/Thumb single step.
Create a DS2_UNREACHABLE macro

__builtin_trap is not always available.  The particular use of it was indented
to indicate that the code path is not reachable.  Create a DS2_UNREACHABLE macro
to aid in marking the location as such across various compilers.
Remove useless #includes from Base.h and move to appropriate files.
Correctly handle split-reads of auxv data.
Use AnyProcessId instead of AllProcessId when none is specified.
Implement attach for debug session.

This commit keeps in place the now-empty SlaveSessionImpl. If it ends up
being purely useless, I'll get rid of it later when I restart working on
platform support.
Ignore packet checksums when we are in noAckMode.

noAckMode implies that checksums should not be checked. Implementations
may simply send "#00" as their checksum.
Separate the run and wait operations in ProcessSpawner.
Move platform-specific support files to their respective directories.
Stop using `assert' in favor of DS2ASSERT.

This makes sure that we get failed assertions in our log files and
uniformizes the output format.
Minor style fixups.

Just ran clang-format on every file.
Get rid of some dead code in ProcessSpawner.