Fixes the update from PR #2508. I had accidentally forgotten to rebuild
the library, and the regression test suite isn't hooked up to the new
fancy build system yet.

I've double checked that the results are deterministic.

Use standard md5 tool on NetBSD.

CMake: Enable only C for lib and programs projects

[regression] Update results.csv

9f327c02 changed the compression method
for LDM, so the results are slightly different.

I've re-tested LDM on some larger inputs and everything seems fine.
These ratio changes just seem to be noise. There is generally a 0.01%
swing in ratio, sometimes better sometimes worse, but never large.

update FreeBSD image to latest 12.2

Stop using deprecated reset?Stream functions

These are replaced by the corresponding context resets. When
converting resetCStream, CCtx_setPledgedSrcSize isn't called if the
source size is "unknown".

This helps reduce the reliance on "static only" symbols, as well as
reducing the use of deprecated functions.

Signed-off-by: Stephen Kitt <steve@sk2.org>

fix ubsan test errors

[fuzz] Fix compiler detection & update ubsan flags

* Fix compiler version regex, which was broken for multi-digit
  versions.
* Fix compiler detection for gcc.
* Disable `pointer-overflow` instead of `integer-overflow` for gcc
  versions newer than 8.0.0.

allows recovering from pointer overflow

Use umask() to Constrain Created File Permissions

This commit addresses #2491.

Note that a downside of this solution is that it is global: `umask()` affects
all file creation calls in the process. I believe this is safe since
`fileio.c` functions should only ever be used in the zstd binary, and these
are (almost) the only files ever created by zstd, and AIUI they're only
created in a single thread. So we can get away with messing with global state.

Note that this doesn't change the permissions of files created by `dibio.c`.
I'm not sure what those should be...

[easy][cli] Add newline to boundary of --help message of --trace and --[no-]check

[bug-fix] Make simple single-pass functions ignore advanced parameters

The simple compression functions are intended to ignore the advanced
parameters, but they were accidentally using them. All the
`ZSTD_parameters` were set correctly, but any extra parameters were
used as-is. E.g. `ZSTD_c_format`.

This PR makes all the simple single-pass functions listed below ignore
the advanced parameters, as intended.

* `ZSTD_compressCCtx()`
* `ZSTD_compress_usingDict()`
* `ZSTD_compress_usingCDict()`
* `ZSTD_compress_advanced()`
* `ZSTD_compress_usingCDict_advanced()`

It also adds a test case that ensures that each of these functions
ignore the advanced parameters.

[lib] Set appliedParams.compressionLevel correctly

Forward the correct compressionLevel to the appliedParams in all cases.
It was already correct for the advanced API, so only the old single-pass
functions needed to be fixed.

This compression level is unused by the library, but is set so that the
tracing framework can consume it.

[trace] Minor fixes found during integration

* Mark `ZSTD_CCtx_getParameter()` as const
* Add `extern "C"` guards to `zstd_trace.h`

New algorithms for the long distance matcher

This avoids a GNU coreutils dependency.

-n is used to match the output format of coreutils:
http://man.netbsd.org/md5.1

[trace] Keep track of a uint64_t tracing context

The most common information that you want to track between begin() and
end() is the timestamp of the begin function, so you can measure the
duration of the (de)compression call. Allow the tracing library to put
this information inside the `ZSTD_TraceCtx`, so it doesn't need to keep
a global map in this case. If a single uint64_t is not enough, the
tracing library can return a unique identifier (like the context
pointer) instead, and use it as a key in a map.

This keeps the simple case simple.

Add (de)compression tracing functionality

[zstd] Fix NULL pointer addition in ZSTD_checkContinuity()

Don't start a new section when `dstSize == 0` to avoid NULL
pointer addition.

minor: removed flackey gcc6 tests from github actions

fixed minor cast warning

from github actions.
replaced by equivalent "current" gcc tests when it makes sense