This commit:
* renames all remaining instances of "DRAM" (which is ambiguous)
to "LUTRAM" (which is not), finishing the work started in
the commit 698ab9be;
* renames memory rule files to brams.txt/lutrams.txt;
* adds/renames script labels map_bram/map_lutram;
* extracts where necessary script labels map_ffram and map_gates;
* adds where necessary options -nobram/-nolutram.
The end result is that BRAM/LUTRAM/FFRAM aspects of every target
are now consistent with each other.
Per architecture:
* anlogic: rename drams.txt→lutrams.txt, add -nolutram, add
:map_lutram, :map_ffram, :map_gates
* ecp5: rename bram.txt→brams.txt, lutram.txt→lutrams.txt
* efinix: rename bram.txt→brams.txt, add -nobram, add :map_ffram,
:map_gates
* gowin: rename bram.txt→brams.txt, dram.txt→lutrams.txt,
rename -nodram→-nolutram (-nodram still recognized), rename
:bram→:map_bram, :dram→:map_lutram, add :map_ffram, :map_gates
On some architectures, notably on Windows, the official name for the
Python binary from python.org is `python`. The build system assumes
that python is called `python3`, which breaks under this architecture.
There is already infrastructure in place to determine the name of the
Python binary when building PYOSYS. Since Python is now always required
to build Yosys, enable this check universally which sets the
`PYTHON_EXECUTABLE` variable.
Then, reuse this variable in other Makefiles as necessary, rather than
hardcoding `python3` everywhere.
Signed-off-by: Sean Cross <sean@xobs.io>
