Add comment about buglet in FIND-DEFSTRUCT-DESCRIPTION.
Remove detritus from pretty-printer dispatch mechanism.

COMPUTE-TEST-FN's implementation was largely historical baggage due to
the CONS type specifier only existing in the atom form as far as the
language was concerned. Discriminating on CAR was just for the pprinter.

*PRECOMPILED-PPRINT-DISPATCH-FUNS* didn't work as intended.
It assumed that the first argument to SET-PPRINT-DISPATCH might match a
known entry, but not only was the FUNCTION-CALL type never used for a
builtin entry, it is neither a type-specifier nor external symbol.
Fix disassembler glitch on x86-64.

If a disassembly terminated at a #x48 byte not as part of a complete
instruction, the labelling pass left a random REX prefix in the state
which the display pass erroneously picked up.
Remove obsolete comment
Export unquoting COMMA readers from SB-INT, and trivial cleanup.
Preserve quasiquotation in SB-CLTL2:MACROEXPAND-ALL
Remove inapplicable comments re formerly flaky test, since fixed.
fix find-defstruct-description's errorp flag
Fix first half of lp#1354606 for splicing in quasiquoted vectors.
Fix undefined behavior case of lp#1354606
Fix lp#1354623 - macroexpansion of QUASIQUOTE broken by rev.88411384
Transform (STRING sym) to (SYMBOL-NAME sym)
Fix WITH-PACKAGE-ITERATOR for empty list of packages
":IMPORTANT NIL" in DEFTRANSFORM now means really unimportant.

Users aren't likely to be able to make code more efficient when
shown "The first argument is a T, not a (NOT NULL)" so don't.
(It only worries them)
Document some bugs in package manipulation.
Improve DOCUMENTATION tests

* Use new helper function ASSERT-DOCUMENTATION

* Consistently use WITH-TEST

* Group all DOCUMENTATION tests in one section of the file
DOCUMENTATION works on instances of FUNCALLABLE-STANDARD-CLASS

Previously, methods on DOCUMENTATION and (SETF DOCUMENTATION) were
specialized on STANDARD-CLASS, excluding FUNCALLABLE-STANDARD-CLASS.

While this was in line with the method signatures listed in the CLHS
entry for DOCUMENTATION, that entry also states (for DOC-TYPE equal to
TYPE):

  If x is a symbol, returns the documentation string of the class whose
  name is the symbol x [...]

indicating that (documentation CLASS-NAME 'type) should work for all
kinds of classes.

Specializing the four methods on CLASS instead STANDARD-CLASS is
1) sufficient to enable operation on FUNCALLABLE-STANDARD-CLASS
2) safe since the accessed %DOCUMENTATION slot is located in CLASS
Extract the state machine of WITH-PACKAGE-ITERATOR into a function.

Also, by avoiding POSITION-IF and FIND-SYMBOL, not to mention the
useless (THE HASH-VECTOR) everywhere, it's significantly faster.
Add WITH-TEST, improve test for DOCUMENTATION on (SETF ...)
Test DOCUMENTATION for DOC-TYPEs PACKAGE, VARIABLE