BasilIR.cf update from obasil: phi, var load/store, named params

[katrinafyi]

compared to obasil, changes the phi block syntax to use square brackets to avoid ambiguity with simulassign statement.

see src/test/scala/ir/ParserTest.scala to learn the effect of phi blocks and named call params. these get lowered into sbasil simul assigns and unnamed params.

[katrinafyi]

ci failing is definitely a line ending problem

[agle]

compared to obasil, changes the phi block syntax to use square brackets to avoid ambiguity with simulassign statement.

I would prefer round brackets, square brackets are used to give the impression of a sequence of nonatomic operations, phis don't have evaluation order etc it seems odd, the phi list is semantically the same as a simulassign and i wanted the syntax to point to that.

Instead the ambiguity could be fixed by moving the phi list before the block's statement list, this gives the impression of block parameters which I don't hate.

[agle]

LGTM

[katrinafyi]

you want this? any suggestions for the indentation?

  block %inputs2
  (
    var R29:bv64 := phi(%inputs -> R29_in:bv64, %inputs2 -> R30_in:bv64),
  )
  [
    goto (%inputs);
  ];

or maybe

  block %inputs2 [
    phi( R29:bv64 := ( %inputs -> R29_in:bv64, %inputs2 -> R30_in:bv64 ) );
    goto (%inputs);
  ];

[agle]

The first option, indentation can be the same as it already is.