Add ld.so linker scripts on the remaining platforms.

For more archs, ld.so itself only needs/uses the arch's "just add load offset"
'relative' relocation. Take advantage of that to simplify ld.so's self-reloc
code:
* give the exceptional archs (hppa and mips64) copies of the current boot.c
as boot_md.c
* teach the Makefile to use boot_md.c when present
* reduce boot.c down to the minimum necessary to handle just relative reloc
* teach the Makefile to fail if the built ld.so has other types of relocs

ok visa@ kettenis@

Delete superfluous libc reacharounds.
Replace magic numbers with symbolic constants in ldasm.S
Let the kernel do the cacheflush optimization.

from miod@

A first cut at ld.so bits for m88k. Lazy binding is currently disabled as it
does not work beyond the first few lazy resolver calls. But that's already
enough to run simple binaries.

For more archs, ld.so itself only needs/uses the arch's "just add load offset"
'relative' relocation. Take advantage of that to simplify ld.so's self-reloc
code:
* give the exceptional archs (hppa and mips64) copies of the current boot.c
as boot_md.c
* teach the Makefile to use boot_md.c when present
* reduce boot.c down to the minimum necessary to handle just relative reloc
* teach the Makefile to fail if the built ld.so has other types of relocs

ok visa@ kettenis@

Delete superfluous libc reacharounds.
Replace magic numbers with symbolic constants in ldasm.S
Let the kernel do the cacheflush optimization.

from miod@

A first cut at ld.so bits for m88k. Lazy binding is currently disabled as it
does not work beyond the first few lazy resolver calls. But that's already
enough to run simple binaries.

Delete superfluous libc reacharounds.
Replace magic numbers with symbolic constants in ldasm.S
Let the kernel do the cacheflush optimization.

from miod@

A first cut at ld.so bits for m88k. Lazy binding is currently disabled as it
does not work beyond the first few lazy resolver calls. But that's already
enough to run simple binaries.