Add sizeof for arrays of integral types (#8445)

tests/misc/tsizeof.nim

@@ -1,5 +1,7 @@
-# Test the sizeof proc
-
+discard """
+  file: "tsize.nim"
+  output: "40 3 12 32"
+"""
 type
   TMyRecord {.final.} = object
     x, y: int
@@ -7,4 +9,20 @@ type
     r: float
     s: string
 
+  TMyEnum = enum
+    tmOne, tmTwo, tmThree, tmFour
+
+  TMyArray1 = array[3, uint8]
+  TMyArray2 = array[1..3, int32]
+  TMyArray3 = array[TMyEnum, float64]
+
+const 
+  mysize1 = sizeof(TMyArray1)
+  mysize2 = sizeof(TMyArray2)
+  mysize3 = sizeof(TMyArray3)
+
 write(stdout, sizeof(TMyRecord))
+echo ' ', mysize1, ' ', mysize2, ' ',mysize3
+
+
+