stage2: clean up SPU Mk II code

* move SPU code from std to self hosted compiler
 * change std lib comments to be descriptive rather than prescriptive
 * avoid usingnamespace
 * fix case style of error codes
 * remove duplication of producer_string
 * generalize handling of less than 64 bit arch pointers
 * clean up SPU II related test harness code
54f3b0a560Andrew Kelley committed on 8/22/2020, 8:36:08 PMparent24efbf5
11 files changedLine totals unavailable