Inline escape-only prompt bodies in the Tree-IL

Inline escape-only prompt bodies in the Tree-IL

* module/language/scheme/decompile-tree-il.scm (do-decompile):
* module/language/tree-il/analyze.scm (analyze-lexicals):
* module/language/tree-il/canonicalize.scm (canonicalize):
* module/language/tree-il/compile-glil.scm (flatten-lambda-case):
* module/language/tree-il/cse.scm (cse):
* module/language/tree-il/peval.scm (peval):
* test-suite/tests/peval.test ("partial evaluation"):  Partially revert
  178a40928, so that escape-only prompts explicitly inline their bodies.