untangle WITH-IR1-NAMESPACE and WITH-COMPILATION-VALUES

untangle WITH-IR1-NAMESPACE and WITH-COMPILATION-VALUES

 * Move the first out from the latter, and put parts of the first that
   belong in the latter there. They're sufficiently unrelated that
   it's just confusing. Also clarify why some stuff is in W-C-V and
   not W-IR1-N.

 * Places that need W-IR1-N: %COMPILE, COMPILE-LOAD-TIME-STUFF,
   CONVERT-AND-MAYBE-COMPILE. These are our topmost entry points into
   the convert & compile dance.

   ...and PROCESS-TOPLEVEL-LOCALLY, which needs to process
   declarations. We really should separate environment handling and
   compiler.

 * This also removes the unsightly (REMHASH NAME *FREE-FUNS*) hack
   from couple of places.

 * Move *SOURCE-PATHS* binding to WITH-SOURCE-PATHS (new), also
   sufficiently unrelated to be confusing.

 (This fixes the compiler.test.sh regression I managed to introduce.)