lint1: add test for initializing nested structs

Discovered in var.c 1.774 from 2020-12-28.

tests/usr.bin/xlint/lint1/Makefile

@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.17 2020/12/28 09:58:56 rillig Exp $
+# $NetBSD: Makefile,v 1.18 2020/12/28 10:22:21 rillig Exp $
 
 NOMAN=		# defined
 
@@ -60,6 +60,7 @@ FILES+=		d_nested_structs.c
 FILES+=		d_nolimit_init.c
 FILES+=		d_packed_structs.c
 FILES+=		d_shift_to_narrower_type.c
+FILES+=		d_struct_init_nested.c
 FILES+=		d_type_conv1.c
 FILES+=		d_type_conv1.exp
 FILES+=		d_type_conv2.c

tests/usr.bin/xlint/lint1/d_struct_init_nested.c

@@ -0,0 +1,59 @@
+# 2 "d_struct_init_nested.c"
+
+typedef enum O1 { O1C = 101 } O1;
+typedef enum O2 { O2C = 102 } O2;
+typedef enum O3 { O3C = 103 } O3;
+typedef enum I1 { I1C = 201 } I1;
+typedef enum I2 { I2C = 202 } I2;
+
+struct Inner1 {
+	I1 i1;
+};
+
+struct Outer3Inner1 {
+	O1 o1;
+	struct Inner1 inner;
+	O3 o3;
+};
+
+O1
+funcOuter3Inner1(void)
+{
+	struct Inner1 inner = {
+		I1C
+	};
+	struct Outer3Inner1 o3i1 = {
+	    O1C,
+	    inner,
+	    O3C
+	};
+
+	return o3i1.o1;
+}
+
+struct Inner2 {
+	I1 i1;
+	I2 i2;
+};
+
+struct Outer3Inner2 {
+	O1 o1;
+	struct Inner2 inner;
+	O3 o3;
+};
+
+O1
+funcOuter3Inner2(void)
+{
+	struct Inner2 inner = {
+		I1C,
+		I2C
+	};
+	struct Outer3Inner2 o3i2 = {
+	    O1C,
+	    inner,
+	    O3C
+	};
+
+	return o3i2.o1;
+}

tests/usr.bin/xlint/lint1/t_integration.sh

@@ -1,4 +1,4 @@
-# $NetBSD: t_integration.sh,v 1.6 2020/12/28 09:58:56 rillig Exp $
+# $NetBSD: t_integration.sh,v 1.7 2020/12/28 10:22:21 rillig Exp $
 #
 # Copyright (c) 2008, 2010 The NetBSD Foundation, Inc.
 # All rights reserved.
@@ -71,6 +71,8 @@ test_case check_valid c9x_recursive_init "Checks C9X struct/union member" \
     "init, with nested union and trailing member"
 test_case check_valid nested_structs "Checks nested structs"
 test_case check_valid packed_structs "Checks packed structs"
+test_case check_invalid struct_init_nested \
+    "Initialization of nested structures"
 
 test_case check_valid cast_init "Checks cast initialization"
 test_case check_valid cast_init2 "Checks cast initialization as the rhs of a" \