[MC/DC] Update CoverageMapping tests (#125404)
To resolve the error, rename mcdc-error-nests.cpp ->
mcdc-nested-expr.cpp at first.
- `func_condop` A corner case that contains close decisions.
- `func_expect` Uses `__builtin_expect`. (#124565)
- `func_lnot` Contains logical not(s) `!` among MC/DC binary operators.
(#124563)
