Tracking: Call type checking

[onbjerg]

Describe the feature

Tracking issue to capture all variants of type checking for ExprKind::Call here:

solar/crates/sema/src/typeck/checker.rs

Lines 150 to 179 in f6cf16d

	hir::ExprKind::Call(callee, ref args, ref _opts) => {
	let mut callee_ty = self.check_expr(callee);
	// Get the function type for struct constructors.
	if let TyKind::Type(struct_ty) = callee_ty.kind
	&& let TyKind::Struct(id) = struct_ty.kind
	{
	callee_ty = struct_constructor(self.gcx, struct_ty, id);
	}
	// TODO: `array.push() = x;` is the only valid call lvalue
	let is_array_push = false;
	let ty = match callee_ty.kind {
	TyKind::FnPtr(_f) => {
	// dbg!(callee_ty);
	todo!()
	}
	TyKind::Type(to) => self.check_explicit_cast(expr.span, to, args),
	TyKind::Event(..) | TyKind::Error(..) => {
	// return callee_ty
	todo!()
	}
	TyKind::Err(_) => callee_ty,
	_ => {
	let msg =
	format!("expected function, found `{}`", callee_ty.display(self.gcx));
	let mut err = self.dcx().err(msg).span(callee.span);
	err = err.span_note(expr.span, "call expression requires function");
	self.gcx.mk_ty_err(err.emit())
	}
	};

Refer to the parent tracking issue for guidance on working on the typechecker.

Additional context

No response