Introduce SptEntry.
TMP-Revert: 73b499a0a7e17e585813de8dbf25ca193a009d9b
WIP
Float out debug version of SptEntry
TMP: no not use 'a' in SPT, this is a temporary step just to try to move forward'
Fix production of SPT entries in the desugarer.
Implement per-module SPT tables in Cmm.
Make SPE keys null terminated.
SPT module initialization basic