https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127173
--- Comment #1 from Senthil Kumar Selvaraj <saaadhu at gcc dot gnu.org> --- Debugging shows that contracts.cc:1370 assumes expr_first (DECL_SAVED_TREE (fndecl)) must be a MUST_NOT_THROW_EXPR expr. That is true if flag_enforce_eh_specs is true. With -fno-enforce-eh-specs, that flag is false, and because decl.cc:use_eh_spec_block then returns false, begin_eh_spec_block doesn't get to wrap the function body in a MUST_NOT_THROW_EXPR, triggering the crash.
