hdl._ast: fix _value_repr computation.

Fixes fallout from #1165.

tests/test_hdl_ast.py

@@ -1321,6 +1321,7 @@ class SignalTestCase(FHDLTestCase):
         s = Signal(decoder=Color)
         self.assertEqual(s.decoder(1), "RED/1")
         self.assertEqual(s.decoder(3), "3")
+        self.assertRepr(s._value_repr, "(Repr(FormatEnum(Color), (sig s), ()),)")
 
     def test_enum(self):
         s1 = Signal(UnsignedEnum)
@@ -1328,6 +1329,7 @@ class SignalTestCase(FHDLTestCase):
         s2 = Signal(SignedEnum)
         self.assertEqual(s2.shape(), signed(2))
         self.assertEqual(s2.decoder(SignedEnum.FOO), "FOO/-1")
+        self.assertRepr(s2._value_repr, "(Repr(FormatEnum(SignedEnum), (sig s2), ()),)")
 
     def test_const_wrong(self):
         s1 = Signal()
@@ -1335,6 +1337,10 @@ class SignalTestCase(FHDLTestCase):
                 r"^Value \(sig s1\) cannot be converted to an Amaranth constant$"):
             Const.cast(s1)
 
+    def test_value_repr(self):
+        s = Signal()
+        self.assertRepr(s._value_repr, "(Repr(FormatInt(), (sig s), ()),)")
+
 
 class ClockSignalTestCase(FHDLTestCase):
     def test_domain(self):

tests/test_lib_data.py

@@ -458,6 +458,11 @@ class ViewTestCase(FHDLTestCase):
         self.assertIsInstance(cv, Signal)
         self.assertEqual(cv.shape(), unsigned(3))
         self.assertEqual(cv.name, "v")
+        self.assertRepr(cv._value_repr, """
+        (Repr(FormatInt(), (sig v), ()),
+            Repr(FormatInt(), (slice (sig v) 0:1), ('a',)),
+            Repr(FormatInt(), (slice (sig v) 1:3), ('b',)))
+        """)
 
     def test_construct_signal_init(self):
         v1 = Signal(data.StructLayout({"a": unsigned(1), "b": unsigned(2)}),

tests/test_lib_enum.py

@@ -137,6 +137,7 @@ class EnumTestCase(FHDLTestCase):
             B = -3
         a = Signal(EnumA)
         self.assertRepr(a, "(sig a)")
+        self.assertRepr(a._value_repr, "(Repr(FormatEnum(EnumA), (sig a), ()),)")
 
     def test_enum_view(self):
         class EnumA(Enum, shape=signed(4)):