feat: evaluate compile-time aggregates and explicit expressions

source/lower/lower.hon

@@ -1795,6 +1795,9 @@ lower_expression proc(state @mut State, id ast.NodeId) ir.ValueId ! (mem.AllocEr
     }
     if (typecheck.is_union_variant(state.checked, id)) return try lower_union(state, id)
     match ast.expr_kind(tree, id) {
+        .comptime_expr: {
+            if (!trap_type(state, id)) unreachable
+        }
         .typed_constant: {
             if (trap_type(state, id)) return ir.no_value
             return try lower_as(state, ast.typed_constant(tree, id).value, typecheck.type_of(state.checked, id))
@@ -2130,6 +2133,12 @@ exact_float_integer proc(text []u8, value f64) bool {
 @hide:file
 lower_number proc(state @mut State, id ast.NodeId) ir.ValueId ! (mem.AllocError | diagnostics.CapacityError) {
     span :: ast.node_span(state.tree, id)
+    if (ast.float_value(state.tree, id)) |value| {
+        return try constant(state, ir.Value{
+            type = .float,
+            data = ir.ValueData{ real = value },
+        }, span)
+    }
     text :: ast.literal_text(state.tree, id)
     type :: lower_type(state, typecheck.type_of(state.checked, id))
     if (ir.integer_bits(type) != 0 and !ir.unsigned_integer(type)) {