Don't try and get enum value if its invalid (#22997)

Currently running `nimsuggest`/`check` on this code causes the compiler
to raise an exception

```nim
type
  Test = enum
    A = 9.0 
```

```
assertions.nim(34)       raiseAssert
Error: unhandled exception: int128.nim(69, 11) `arg.sdata(3) == 0` out of range [AssertionDefect]
```

Issue was the compiler still trying to get the ordinal value even if it
wasn't an ordinal

1 files changed, 8 insertions, 0 deletions

diff --git a/tests/enum/tenum_invalid.nim b/tests/enum/tenum_invalid.nim
new file mode 100644
index 000000000..8ae0a1057
--- /dev/null
+++ b/tests/enum/tenum_invalid.nim
@@ -0,0 +1,8 @@
+discard """
+cmd: "nim check $file"
+"""
+
+type
+  Test = enum
+    A = 9.0 #[tt.Error
+        ^ ordinal type expected; given: float]#