Improve run_test.sh to check against NRN.

[1uc]

We can run run_test.sh with a special generated by nocmodl. This helps debug simulate.py itself, which is useful when things get very subtle.

[1uc]

Merge after #1134.

[1uc]

An example of when is this useful is:

INITIAL {
  x = 42
}

BREAKPOINT {
  x = c
}

and now the question is should x[0] == 42.0 or x[0] == c? This is risky to answer without checking against NRN + nocmodl.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (e520d76) 88.31% compared to head (8b1557e) 88.31%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1135   +/-   ##
=======================================
  Coverage   88.31%   88.31%           
=======================================
  Files         175      175           
  Lines       12983    12983           
=======================================
  Hits        11466    11466           
  Misses       1517     1517           

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[bbpbuildbot]

Logfiles from GitLab pipeline #184572 (:white_check_mark:) have been uploaded here!

Status and direct links:

• ✅ spack_setup
• ✅ build:intel
• ✅ build:nvhpc
• ✅ test:intel
• ✅ test:nvhpc