fix: src\array.c(86): warning C4244: '=': conversion from 'mrb_int' to...

fix: src\array.c(86): warning C4244: '=': conversion from 'mrb_int' to 'uint32_t', possible loss of data

include/mruby/array.h

@@ -45,7 +45,7 @@ struct RArray {
 #define ARY_EMBED_P(a) ((a)->flags & MRB_ARY_EMBED_MASK)
 #define ARY_UNSET_EMBED_FLAG(a) ((a)->flags &= ~(MRB_ARY_EMBED_MASK))
 #define ARY_EMBED_LEN(a) ((mrb_int)(((a)->flags & MRB_ARY_EMBED_MASK) - 1))
-#define ARY_SET_EMBED_LEN(a,len) ((a)->flags = ((a)->flags&~MRB_ARY_EMBED_MASK) | (len + 1))
+#define ARY_SET_EMBED_LEN(a,len) ((a)->flags = ((a)->flags&~MRB_ARY_EMBED_MASK) | ((uint32_t)(len) + 1))
 #define ARY_EMBED_PTR(a) (&((a)->as.embed[0]))
 
 #define ARY_LEN(a) (ARY_EMBED_P(a)?ARY_EMBED_LEN(a):(a)->as.heap.len)