void-payloads, multi-pattern arms, and range patterns (match statements)

compiler/ast/ast.odin

@@ -178,10 +178,14 @@ Stmt :: struct {
 	// `Defer` statements use `update` as the deferred statement (which may itself
 	// be a `Block`).
 	// `Match` statements use `expr` as the subject and `body` as the list of arm
-	// statements (each a `Match_Arm`). A `Match_Arm` uses `expr` as its pattern
-	// (`INVALID_EXPR` marks the `else` arm), `captures` for the optional payload
-	// capture (0 or 1 name, tagged-union variants only), and `body` as the arm body.
+	// statements (each a `Match_Arm`). A `Match_Arm` uses `patterns` as its pattern
+	// list (empty marks the `else` arm; more than one is a multi-pattern arm),
+	// `captures` for the optional payload capture (0 or 1 name, tagged-union variants
+	// only) with `pointer_capture` distinguishing `|@cap|` from `|cap|`, and `body`
+	// as the arm body.
 	captures:   []symbol.Id,
+	// `Match_Arm` pattern list; empty ⇒ the `else` arm.
+	patterns:   []Expr_Id,
 	guard:      Expr_Id,
 	body:       []Stmt_Id,
 	else_body:  []Stmt_Id,
@@ -303,6 +307,7 @@ destroy_module :: proc(module: ^Module) {
 	}
 	for statement in module.statements {
 		delete(statement.captures, module.allocator)
+		delete(statement.patterns, module.allocator)
 		delete(statement.body, module.allocator)
 		delete(statement.else_body, module.allocator)
 	}