[tests] test case for bug in handling array initialization from string

tests/syntax/init_array_string.i

+char* ptr = "A" "B";
+
+char* ptr2 = ("A" "B");
+
+char a[] = "A" "B";
+
+char b[] = ("A" "B");
+
+char c[] = "ABC";
+
+char d[] = ("ABC");

tests/syntax/oracle/init_array_string.res.oracle

+[kernel] Parsing init_array_string.i (no preprocessing)
+/* Generated by Frama-C */
+char *ptr = (char *)"AB";
+char *ptr2 = (char *)"AB";
+char a[3] = {(char)'A', (char)'B', (char)'\000'};
+char b[3] = {(char)'A', (char)'B', (char)'\000'};
+char c[4] = {(char)'A', (char)'B', (char)'C', (char)'\000'};
+char d[4] = {(char)'A', (char)'B', (char)'C', (char)'\000'};
+