unary minus

compiler/ast/ast.odin

@@ -74,13 +74,14 @@ Expr_Kind :: enum u8 {
 	Invalid,
 	Integer,
 	Name,
+	Negate,
 	Add,
 	Call,
 }
 
 Expr :: struct {
 	span:       source.Span,
-	integer:    i64,
+	integer:    u64,
 	args:       []Expr_Id,
 	qualifier:  symbol.Id,
 	name:       symbol.Id,