VCS elaborate.log doesn't show -debug_access; record build flags yourself

VCS: to find out whether an existing simv was built with -debug_access (which costs a lot of runtime on large designs), don't grep elaborate.log. VCS W-2024.09 doesn't echo the vcs command line or its debug flags into the elaboration log, so grepping it for -debug_access/-kdb/-lca finds nothing even when the flags were used. Check the build script or wrapper that invoked vcs, or save the exact command next to the simv when you build it, e.g. write it to a build-flags.txt. When comparing dump-capture overhead (FSDB vs a custom VPI/DPI writer), keep the debug build and the no-debug build in separate directories, so a benchmark run never picks up the wrong simv.