Ported the D64906 technique to AArch64. It deletes 3 alignments at
PT_LOAD boundaries for the default case: the size of an aarch64 binary
can be decreased by at most 192kb.
If sh_addralign(.tdata) < sh_addralign(.tbss),
we can potentially make p_vaddr(PT_TLS)%p_align(PT_TLS) != 0.
ld.so that are known to have problems if p_vaddr%p_align!=0:
- musl<=1.1.22
- FreeBSD 13.0-CURRENT (and before) rtld-elf arm64
New test aarch64-tls-vaddr-align.s checks p_vaddr%p_align = 0.