fix(benchmarks): strip block comments before counting LOC (#232)

loc.js filtered comments line by line, so /* ... */ block comments whose
continuation lines are not *-aligned had their inner lines counted as code.
A plain indented block comment scored higher than the same code written
JSDoc-style. Strip /* ... */ before the line count so both are equal, and
add loc.test.js to lock the behavior.

Fixes #231