fortran_fixed-form does not highlight "dimension" syntax

When `Implicit real*8(a-h,o-z)` is declared, `dimension` syntax can be used to define an array's dimension:

```fortran
DIMENSION myArray1(<size1>, <size2>, <size3>, ... ), myArray2(<size1>, <size2>, <size3>, ... ), ...
```

But fortran_fixed-form does not highlight this syntax. 
