add _Generic test

tests/tests2/94_generic.c

@@ -0,0 +1,51 @@
+#include <stdio.h>
+
+const int a = 0;
+
+struct a {
+	int a;
+};
+
+struct b {
+	int a;
+};
+
+int a_f()
+{
+	return 20;
+}
+
+int b_f()
+{
+	return 10;
+}
+
+#define gen_sw(a) _Generic(a, const char *: 1, default: 8, int: 123);
+
+int main()
+{
+	int i = 0;
+	struct b titi;
+	const int * const ptr;
+	const char *ti;
+
+	i = _Generic(a, int: a_f, const int: b_f)();
+	printf("%d\n", i);
+	i = _Generic(ptr, int *:1, int * const:2, default:20);
+	printf("%d\n", i);
+	i = gen_sw(a);
+	printf("%d\n", i);
+	i = _Generic(titi, struct a:1, struct b:2, default:20);
+	printf("%d\n", i);
+	i = _Generic(a, char:1, int[4]:2, default:5);
+	printf("%d\n", i);
+	i = _Generic(17, int :1, int **:2);
+	printf("%d\n", i);
+	i = _Generic(17L, int :1, long :2);
+	printf("%d\n", i);
+	i = _Generic("17, io", const char *:1, char *:3, const int :2);
+	printf("%d\n", i);
+	i = _Generic(ti, const char *:1, char *:3, const int :2);
+	printf("%d\n", i);
+	return 0;
+}

tests/tests2/94_generic.expect

@@ -0,0 +1,9 @@
+20
+20
+123
+2
+5
+1
+2
+3
+1