Log Message:
Update to 1.8.6.  Adjust patch-ah slightly for new upstream code.
Delete patch-aa as the whole lt_preloaded_symbols bit is gone upstream.

Changes in 1.8.6 (since 1.8.5)

* New features (see the manual for details)

** New convenience function `scm_c_symbol_length ()'

** Single stepping through code from Emacs

When you use GDS to evaluate Scheme code from Emacs, you can now use
`C-u' to indicate that you want to single step through that code. See
`Evaluating Scheme Code' in the manual for more details.

** New "guile(1)" man page!

* Changes to the distribution

** Automake's `AM_MAINTAINER_MODE' is no longer used

Thus, the `--enable-maintainer-mode' configure option is no longer
available: Guile is now always configured in "maintainer mode".

** `ChangeLog' files are no longer updated

Instead, changes are detailed in the version control system's logs.  See
the top-level `ChangeLog' files for details.

* Bugs fixed

** `symbol->string' now returns a read-only string, as per R5RS
** Fix incorrect handling of the FLAGS argument of `fold-matches'
** `guile-config link' now prints `-L$libdir' before `-lguile'
** Fix memory corruption involving GOOPS' `class-redefinition'
** Fix possible deadlock in `mutex-lock'
** Fix build issue on Tru64 and ia64-hp-hpux11.23 (`SCM_UNPACK' macro)
** Fix build issue on mips, mipsel, powerpc and ia64 (stack direction)
** Fix build issue on hppa2.0w-hp-hpux11.11 (`dirent64' and `readdir64_r')
** Fix build issue on i386-unknown-freebsd7.0 ("break strict-aliasing \ 
rules")
** Fix misleading output from `(help rationalize)'
** Fix build failure on Debian hppa architecture (bad stack growth detection)
** Fix `gcd' when called with a single, negative argument.
** Fix `Stack overflow' errors seen when building on some platforms
** Fix bug when `scm_with_guile ()' was called several times from the
   same thread
** The handler of SRFI-34 `with-exception-handler' is now invoked in the
   dynamic environment of the call to `raise'
** Fix potential deadlock in `make-struct'
** Fix compilation problem with libltdl from Libtool 2.2.x
** Fix sloppy bound checking in `string-{ref,set!}' with the empty string