Signed-off-by: Myrtle Shah <gatecat@chipflow.io>

Signed-off-by: Myrtle Shah <gatecat@chipflow.io>

The CMake version set was so old that obsolete policies were being
enabled and breaking FindPython. 2.8 should still be old enough not to
cause problems for any current users.

Signed-off-by: Myrtle Shah <gatecat@chipflow.io>

This field has been deprecated in Python 3 and no longer exists at all
in Python 3.9, causing a build error.

Signed-off-by: Myrtle Shah <gatecat@chipflow.io>

Signed-off-by: gatecat <gatecat@ds0.me>

    large enough instead of creating one big via along the horizontal
    cell power lines, we create one big VIA at each end. To avoid to
    create too massive obstructions.
      But the thresold was too high for cmos45, leading to short with
    the clock tree trunk.

* Change: In bootstrap/coriolisEnv.py, when all tries to locate the
    installation root in predefined locations, try the directory the
    script is installed in.
      This allows for a user to use an installation made in another
    user's account.

* Bug: In Anabatic::_desaturate(), the set of invalidated GCells was never
    cleared between iterations of desaturated GCells. This was not a
    memory leak per se because, in the end, the set was freed. But it did
    induce a gigantic bloating in memory. This finally explain the strange
    slow down in that stage.
      Detected in ls180+cmos45.
* Change: In Anabatic::GCell, add a flag for each depth to avoid
    desaturating twice the same GCell (maybe not needed now that the
    bug is corrected, but it ensure a no-looping).

* Bug: In cumulus/plugins.block.configuration.GaugeConf.expandMinArea(),
    The minimal length of the segment intermediate wires where computed
    for the minimal area using an integer division ( // ), which is
    stupid for less than 1.0 values. They are real quantities at this
    point...
      This was making the DRC of ls180 failing.

Note: We don't suppress warnings due to unused variables or functions,
      as we may need them later or in debug mode...

* Change: In Hurricane::DBo::~DBo, add a noexcept(false) because
    constructed by default destructor of derived classes seems to
    loosen it. The right solution whould be to explicitely define
    all virtual destructors (too lazy for now).
* Change: In Viewer::Script, replace the deprecated
    PyModule_GetFilename() by PyModule_GetFilenameObject(), Unicode
    support again...

* Change: In bootstrap/coriolisEnv.py, the script was looking to
    pythonX.Y (like "python2.7" or "python3.6") only. Now added
    "major" only directories like "python2" or "python3".

* Bug: In Hurricane::Backtrace(), the std::regex supplied by gcc 4.8.5
    seems to be buggy. So, for now, to compile on my reference system,
    revert to C POSIX.

* Bug: In Anabatic::AntennaProtect, if the diode cell exists *but* the
    maximum wire length for a diode is *not* defined (so zero) cancel
    the diode protection instead of making a divide by zero.

* Change: In Isobar3::PyWrapper, C++ exceptions where not catcheds,
    forgot to call exceptionWrapper().
* Change: In Isobar3, remove unused pyToC<>() flavor where T is a
    simple pointer and the argument is also a simple pointer, does
    not make sense.