[libre-riscv-dev] Updating the build script to run from any directory

[lkcl]

ok daniel i marked things TODO, here:
https://git.libre-riscv.org/?p=riscv-tests.git;a=blobdiff;f=isa/rv64ui/sv_addw_elwidth.S;h=8da831c544e75e89d8acf0c7077c02ba552a92dd;hp=fad659d57630044edefc1e36860a4048f1c28aba;hb=1698a24d78589658200136c1c466f043ebbb0165;hpb=a11b75d5e780733325a53e13a665c79719ad49c9

it's real *real* simple.  that's really very important.  one error and
it's several *hours* of debugging, so the less that can be done in one
go, the better.

the trick is to make as many of those tiny absolutely dead-simple
incremental changes as you can, in a "chain", making absolutely sure
at all times that the tests pass, or that more tests are added, etc.
etc.

again, i could do this in 5 minutes, that's not the point: the point
is, *you* wanted to learn, so have at it :)

l.