typo
scribble/base: extend `verbatim` to accept non-string arguments
raco setup: avoid duplicate "scribble.css" files, improve style customization

Arrange for documentation added through an installation-wide package to
use the installation's "scribble.css", etc., files. Also, add "doc-site.css"
and "doc-site.js" files (both empty) to allow installation-specific customization
that will not get overwritten by document installs or builds.
raco pkg install: drop redundant "COPYING.txt" and "COPYING_LESSER.txt"

When adding a package installation-wide, drop redundant "COPYING.txt"
and "COPYING_LESSER.txt" files (i.e., ones that are the same as the
ones the "share" directory of a Racket installation).

This rule is ad hoc, but it avoids almost 150 copies of the file in
the main distribution.
fix some variable-initialization problems/warnings
raco setup: guard a documentation timestamp comparison
subprocess docs: add notes about exec failure and full-pipe deadlock

Closes PR 14003 and 13914
syntax/for-body: adjust docs to clarify why it exists
minor JIT instruction improvement
ARM JIT: make calls & returns visible for branch prediction

This improvement makes `inflate` about 5% faster on
one test platform (with no change on a much older one).