rtld-elf has some vestigial support for building as a static executable. rS45501 introduced an incomplete implementation with a prescient note that it "might never be enabled." r153515 introduced ELF symbol versioning support, and removed part of the unused build infrastructure for static rtld. Differences resulting from the use of alternate toolchains break rtld's run-time dynamic executable check (PR 214972). Simplify rtld by just removing the unused or broken check.
If we want to restore static rtld support later on we should introduce a build-time flag that we can test with #ifdef.