misc testament cleanups (#14764)

* misc testament cleanups extracted cleanups from #14530

* make sure all CI failures can be searched with `FAIL: ` including megatest failures

tests/misc/tunsignedconv.nim

@@ -1,10 +1,4 @@
-discard """
-  output: '''uint
-1'''
-"""
-
 # Tests unsigned literals and implicit conversion between uints and ints
-# Passes if it compiles
 
 var h8:uint8 = 128
 var h16:uint16 = 32768
@@ -53,7 +47,7 @@ block t4176:
 proc fun(): uint = cast[uint](-1)
 const x0 = fun()
 
-echo typeof(x0)
+doAssert typeof(x0) is uint
 
 discard $x0
 
@@ -62,6 +56,6 @@ discard $x0
 const x1 = cast[uint](-1)
 discard $(x1,)
 
-# bug 13698
-let n: csize = 1
-echo n.int32
+# bug #13698
+let n: csize = 1 # xxx should that be csize_t or is that essential here?
+doAssert $n.int32 == "1"