Remove SIMPLE-EVAL-IN-LEXENV with #!+sb-fasteval

Remove SIMPLE-EVAL-IN-LEXENV with #!+sb-fasteval

When *EVALUATOR-MODE* is :COMPILE, the tiny evaluator is redundant
with fasteval. Two small adjustments to fasteval make it do the
same thing that simple-eval was trying to do - avoid compiling
whenever possible, and:
* instead of producing a funcallable instance when encountering
  a FUNCTION operator, punt to the compiler.
* the set of special operators to interpret is smaller than the
  full set of operators that could be interpreted.

Also fix package locks. No new test; an existing test found the bug.