Valid match cases are reported as unreachable

**Describe the bug**
A clear and concise description of the behavior you are seeing and the expected behavior along with steps to reproduce it.

Matching a class instance using string cases (or I guess other literals) causes pyright to report that a case block is unreachable, even if at runtime it works correctly, the object overrides `__eq__`.
Also from my understanding the specification allows such a case, by stating

>In simple terms, LITERAL will succeed only if \ == LITERAL. For the singletons None, True and False, the [is](https://docs.python.org/3/reference/expressions.html#is) operator is used.

https://docs.python.org/3/reference/compound_stmts.html#literal-patterns

**Code or Screenshots**

```python
class X:
__match_args__ = ("a",)

def __init__(self, x, y, a):
self.a = a

def __eq__(self, value: object) -> bool:
return self.a == value.a if isinstance(value, X) else self.a == value

def go_match_str(a: X) -> int | str:
match a:
case "a":
return 1
case "b":
return 2
case _:
return "nope"

def go_match_X(a: X) -> int | str:
match a:
case X("a"):
return 1
case X("b"):
return 2
case _:
return "nope"

def go_if(a: X) -> int | str:
if a == "a":
return 1
elif a == "b":
return 2
else:
return "nope"

xs = [X(1, 1, "a"), X(2, 2, "b"), X(0, 0, "c")]
assert [go_match_str(x) for x in xs] == [1, 2, "nope"]
assert [go_match_X(x) for x in xs] == [1, 2, "nope"]
assert [go_if(x) for x in xs] == [1, 2, "nope"]
```

the code above triggers no assertion errors but accorting to pyright go_match_str will only match the wildcard pattern:

**VS Code extension or command-line**
Are you running pyright as a VS Code extension, a language server in another editor, integrated into Pylance, or the command-line tool? Which version?

the above image is via pylance, but enabling `reportUnreachable = true` pytight on the above code also reports errors:
>13:13 - error: Type analysis indicates code is unreachable
>15:13 - error: Type analysis indicates code is unreachable

version is pyright 1.1.407

Start with the provided go_match_str, go_match_X, and go_if examples and inspect Pyright's pattern-matching and unreachable-code analysis. Compare literal-pattern handling with the runtime assertions and confirm that enabling reportUnreachable no longer marks the valid string cases as unreachable.

Written by the indexing model from the issue text.