glsl: remove remaining is_array variables

Previously the reason we needed is_array was because we used array_size == NULL to
 represent both non-arrays and unsized arrays.  Now that we use a non-NULL
array_specifier to represent an unsized array, is_array is redundant.

Signed-off-by: Timothy Arceri <t_arceri@yahoo.com.au>
Reviewed-by: Paul Berry <stereotype441@gmail.com>
5 files changed