Initial take on LLDB support.
Merge pull request #791 from waywardmonkeys/lldb-tools

Initial take on LLDB support.
[run-time] Disable allocation counts when not using MPS.

This is really needing to target HARP vs others, because the
GC TEB isn't configured correctly in non-HARP run-times.
[rt] Start calling the MPS-style API.
[rt] Map prim_allocate_filled to new API.
[rt,c] Switch more things over to the collector APIs.
[crt] Use GC_MALLOC_ATOMIC where possible.
[rt] Finish calling MPS-style API.
[rt] Call MPS-style API in posix-threads
[crt] Convert primitive_byte_allocate_filled and primitive_byte_allocate_filled_terminated to the new API.
[crt] Remove primitive_byte_allocate().
[crt] Remove instance_header_setter.

I want to remove things that use dylan_value*.
[crt] Just define the byte string and simple object vector structs.

Nothing used the macros to define other instances of the struct.
[crt] Improve type safety of debug-print.c
[crt] Update primitive_raw_as_string to use new MM APIs.