Updated error message per comment
Updated error message per comment

Updated error message for identifier-expression.js to avoid abbreviations per comments
saikobee/squiggle,squiggle-lang/squiggle-lang,squiggle-lang/squiggle-lang,squiggle-lang/squiggle-lang,wavebeem/squiggle,wavebeem/squiggle,saikobee/expr-lang,saikobee/squiggle,saikobee/expr-lang,saikobee/squiggle,wavebeem/squiggle,saikobee/expr-lang