compiler.*: doc improvements
compiler.codegen.gc-maps: initial docs
cpu.architecture: %save-context example
stack-checker,compiler: docs for stack-checker and compiler words
compiler.cfg.*: more docs, tests and a small refactoring of the
admissible-registers word
compiler,cpu: more docs
cpu.*: docs and tests for words in the assembler
compiler.codegen.*: help for resolve-label misplaced -- move it
compiler.cfg.*: more stub docs for cfg construction words
Docs: fixing smaller help-lint nitpicks
compiler.codegen.gc-maps: update docs so that they match how factors gc-maps currently work