Follow-up to r353959 and r368070: do the same for other architectures.
arm32 already seems to use its own .fnstart/.fnend directives, which
appear to be ARM-specific variants of the same thing. Likewise, MIPS
uses .frame directives.
Reviewed by: arichardson
Differential Revision: https://reviews.freebsd.org/D27387
This provides stub implementations of arm64 Linux vdso and machdep,
ptrace, and futex sufficient for executing an arm64 Linux 'hello world'
binary.
Reviewed by: andrew
Sponsored by: Turing Robotic Industries
Differential Revision: https://reviews.freebsd.org/D15832