use doAssert in tests (#16486)

tests/parser/ttypeclasses.nim

@@ -16,31 +16,31 @@ var z: ptr int
 const C = @[1, 2, 3]
 
 static:
-  assert x is ref
-  assert y is distinct
-  assert z is ptr
-  assert C is static
-  assert C[1] is static[int]
-  assert C[0] is static[SomeInteger]
-  assert C isnot static[string]
-  assert C is SEQ|OBJ
-  assert C isnot OBJ|TPL
-  assert int is int
-  assert int is T
-  assert int is SomeInteger
-  assert seq[int] is type
-  assert seq[int] is type[seq]
-  assert seq[int] isnot type[seq[float]]
-  assert i isnot type[int]
-  assert type(i) is type[int]
-  assert x isnot T
-  assert y isnot S
-  assert z isnot enum
-  assert x isnot object
-  assert y isnot tuple
-  assert z isnot seq
+  doAssert x is ref
+  doAssert y is distinct
+  doAssert z is ptr
+  doAssert C is static
+  doAssert C[1] is static[int]
+  doAssert C[0] is static[SomeInteger]
+  doAssert C isnot static[string]
+  doAssert C is SEQ|OBJ
+  doAssert C isnot OBJ|TPL
+  doAssert int is int
+  doAssert int is T
+  doAssert int is SomeInteger
+  doAssert seq[int] is type
+  doAssert seq[int] is type[seq]
+  doAssert seq[int] isnot type[seq[float]]
+  doAssert i isnot type[int]
+  doAssert type(i) is type[int]
+  doAssert x isnot T
+  doAssert y isnot S
+  doAssert z isnot enum
+  doAssert x isnot object
+  doAssert y isnot tuple
+  doAssert z isnot seq
 
   # XXX: These cases don't work properly at the moment:
-  # assert type[int] isnot int
-  # assert type(int) isnot int
+  # doAssert type[int] isnot int
+  # doAssert type(int) isnot int