Testcase for PR c/18282.

From-SVN: r91979

gcc/testsuite/gcc.dg/attr-mode-2.c

+/* PR c/18282 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+typedef int tword __attribute__((mode(word)));
+
+typedef enum { B1 = 1 } B;
+typedef enum { C1 = 1 } C __attribute__ ((mode(QI)));
+typedef enum { D1 = 1 } __attribute__ ((mode(word))) D;
+
+B __attribute__ ((mode (QI))) bqi;
+B __attribute__ ((mode (word))) bword;
+
+int sqi[sizeof (bqi) == 1 ? 1 : -1];
+int sword[sizeof (bword) == sizeof(tword) ? 1 : -1];
+int sc[sizeof (C) == 1 ? 1 : -1];
+int sd[sizeof (D) == sizeof(tword) ? 1 : -1];
+
+int aqi[__alignof (bqi) == 1 ? 1 : -1];
+int aword[__alignof (bword) == __alignof(tword) ? 1 : -1];
+int ac[__alignof (C) == 1 ? 1 : -1];
+int ad[__alignof (D) == __alignof(tword) ? 1 : -1];