Don't process a user pragma if its invalid (#23041)

When running `check`/`suggest` in a file with an invalid user pragma
like
```nim
{.pragma foo: test.}
```
It will continue to try and process it which leads to the compiler
running into a `FieldDefect`
```
fatal.nim(53)            sysFatal
Error: unhandled exception: field 'sons' is not accessible for type 'TNode' using 'kind = nkIdent' [FieldDefect]
```
This makes it instead bail out trying to process the user pragma if its
invalid

0 files changed, 0 insertions, 0 deletions