Change COMPILE-SCODE/INTERNAL/HOOK into three separate hooks:

Change COMPILE-SCODE/INTERNAL/HOOK into three separate hooks:
COMPILE-SCODE/FILE/HOOK, COMPILE-SCODE/NO-FILE/HOOK, and
COMPILE-SCODE/RECURSIVE/HOOK.  Use this in the C back end to fix
compilation of scode not from files.  Handle temporary files more
carefully in the C back end.  Remove vestiges of support for keeping
debugging info in the C back end, which depends on such operations as
SET-COMPILED-CODE-BLOCK/DEBUGGING-INFO! not available in the C code
generator.  The info should perhaps be returned in the compiler
output, and applied in FINISH-C-COMPILATION to the compiled code
block, but this is trickier than it sounds.  For now we'll just not
pretend to support keeping debugging info.