Now parameters can be declared `const`, `@in`, `@out`, `@inout`. `@in`
is redundant as it's the default, but I guess it's nice for
self-documenting code. `const` marks the parameter as read-only in the
function, `@out` and `@inout` allow the parameter to pass the value back
out (by copy), but `@out` does not initialize the parameter before
calling and returning without setting an `@out` parameter is an error
(but unfortunately, currently detected only when optimizing).
Unfortunately, it seems to have broken (only!) v6 progs when optimizing
as the second parameter gets optimized out.
Other than contructors (and problems with the `out` block) qfcc can
compile fstrianglest.vert to what looks like working ruamoko code.
There's still a lot of work to do, though.
That is, `@generic(...) { ... };`, which is handy for bulk declarations
(such as for glsl). This proved to be a lot harder than expected, I
suspect handling of specifiers needs a lot of work.
The expression grammar has been tidied up and some basic checks are made
of parameters to the type functions. Also, type parameters are looked up
so parsing now works properly. However, the type parameters are not used
correctly, so function generation doesn't work.
The semantics are only partially implemented (generic types not yet
generated), but the generic scope for function declarations seems to be
working as intended in that it gets inserted in the scope chain and
removed at the end of the declaration.
