Update crunch bootstrapping test for recent fixes

• r277259 crunchide: Correct 64-bit section header offset
• r281674 crunchide: always include both 32- and 64-bit ELF support

With built-in cross-size support we also no longer need a special case
for cross-build crunchide.

Reviewed by: imp
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D2576