Clean up use of 'iname' variable in generate_sequential_loop_dim_code (found by @mattwala)

mentioned in issue #23 (closed)

All of the failing tests make use of the pattern

{[i]: ...}
  [i] -> {...}

i.e., an iname is used as a data dependent parameter.

added 4 commits

• b948121f - Make iname iteration order in generate_sequential_loop_dim_code deterministic
• 79ee80e5 - Use 'orig_domain' as guiding domain in intersecting kernel with slab in sequential loop codegen
• 0bae9645 - Fix generated for loop code in test_tight_loop_bounds_codegen
• ea2431c3 - Minor comment addition

Compare with previous version

Two fixes:

• islpy@110de04b
• 79ee80e5

enabled an automatic merge when the pipeline for ea2431c3 succeeds

merged

mentioned in commit 55f350c3

mentioned in issue #28 (closed)