vppinfra: add foreach_int macro

foreach_int(x, 1, 3, 5, 7)
   {
     fformat(stdout, "x is %u\n", x);
   }

Type: improvement
Change-Id: Idc355f4a284f421b150e3acb7a3a57bcede408c7
Signed-off-by: Damjan Marion <damarion@cisco.com>

.clang-format

@@ -20,6 +20,7 @@ ForEachMacros:
   - 'vec_foreach_index_backwards'
   - 'vec_foreach_pointer'
   - 'vlib_foreach_rx_tx'
+  - 'foreach_int'
   - 'foreach_vlib_main'
   - 'foreach_set_bit_index'
   - 'foreach_vlib_frame_bitmap_set_bit_index'

src/vppinfra/types.h

@@ -196,6 +196,12 @@ typedef i64 i64u __attribute__ ((aligned (1), __may_alias__));
 typedef word wordu __attribute__ ((aligned (1), __may_alias__));
 typedef uword uwordu __attribute__ ((aligned (1), __may_alias__));
 
+#define foreach_int(__var, ...)                                               \
+  for (int __int_array[] = { __VA_ARGS__ }, *__int_ptr = __int_array,         \
+	   __var = *__int_ptr;                                                \
+       __int_ptr - ARRAY_LEN (__int_array) < __int_array;                     \
+       __var = *++__int_ptr)
+
 #endif /* included_clib_types_h */
 
 /*