I decided to not mess with actual casts. In retrospect, this is probably
for the best as it avoids any bit-cast conflicts, but should allow for
block initializers with a few tweaks. `@construct (type, args...)` in
Ruamoko follows the same path as `type(args...)` in glsl.
They're buggy in that the defspaces for parameters and locals are
incorrect (they need to point to the calling scope's space). Also,
parameters are not yet hooked up correctly. However, errors (because I
need to allow casts from scalars to vectors) do get handled.
The main goal was to make it possible to give generic functions
definitions (since the code would be very dependent on the actual
parameter types), but will also allow for inline functions. It also
helped move a lot of the back-end dependent code out of semantics
processing and almost completely (if not completely) out of the parser.
Possibly more importantly, it gets the dags flushing out of the parser,
which means such is now shared by all front-ends.
There's probably a lot of dead code in expr.c now, but that can be taken
care of another time.
This required adding a `var` symbol type. For now, it holds just the
storage class, but it might be good for the initializer, too.
Also, clean up some pointer/reference inconsistencies.
It wasn't quite as nasty as I thought, but splitting it up helps add a
little self documentation and, possibly more importantly, simplify
navigation through the type checks and argument setup.
I've long felt build_function_call was getting a bit big, and expr.c
especially so. This should make it easier to rewrite build_function_call
for dealing with target-specific code. As a bonus, the int through ...
warning is already cleaned up.
