add tests for recently closed issues (#10722)

tests/misc/tsizeof3.nim

@@ -0,0 +1,19 @@
+discard """
+output: '''
+[0, 0, 0, 0, 0, 0, 48, 57]
+'''
+"""
+# bug #7238
+
+type ByteArrayBE*[N: static[int]] = array[N, byte]
+  ## A byte array that stores bytes in big-endian order
+
+proc toByteArrayBE*[T: SomeInteger](num: T): ByteArrayBE[sizeof(T)]=
+  ## Convert an integer (in native host endianness) to a big-endian byte array
+  ## Notice the result type
+  const N = T.sizeof
+  for i in 0 ..< N:
+    result[i] = byte(num shr ((N-1-i) * 8))
+
+let a = 12345.toByteArrayBE
+echo a