Report an error when the parameter list is missing commas

[turbolent]

• Targeted PR against master branch
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work
• Code follows the standards mentioned here
• Updated relevant documentation
• Re-reviewed Files changed in the Github PR explorer
• Added appropriate labels

[codecov-commenter]

Codecov Report

Merging #1073 (99dedd3) into master (8059460) will increase coverage by 0.04%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1073      +/-   ##
==========================================
+ Coverage   75.53%   75.58%   +0.04%     
==========================================
  Files         270      270              
  Lines       33032    33045      +13     
==========================================
+ Hits        24952    24978      +26     
+ Misses       6956     6948       -8     
+ Partials     1124     1119       -5     

Flag	Coverage Δ
unittests	75.58% <100.00%> (+0.04%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
runtime/parser2/function.go	69.28% <100.00%> (+0.44%)	⬆️
runtime/sema/hints.go	16.66% <0.00%> (-3.34%)	⬇️
runtime/sema/type.go	88.00% <0.00%> (+0.08%)	⬆️
runtime/sema/check_casting_expression.go	96.55% <0.00%> (+0.14%)	⬆️
runtime/interpreter/interpreter.go	91.10% <0.00%> (+0.14%)	⬆️
runtime/sema/checker.go	90.66% <0.00%> (+0.87%)	⬆️
runtime/parser2/parser.go	93.36% <0.00%> (+0.94%)	⬆️

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