changes in sbcl-1.0.49 relative to sbcl-1.0.48:

  * minor incompatible change: WITH-LOCKED-HASH-TABLE no longer disables
    interrupts for its body.
  * enhancement: source locations are now available for files loaded as
    source, compile-time-too evaluation, and initialization files.
  * enhancement: WITH-COMPILATION-UNIT :SOURCE-NAMESTRING allows providing
    virtual source-file information, eg. overriding input-file of COMPILE-FILE
    when a temporary file is used for compilation.
  * enhancement: ASDF has been updated to version 2.015.3.
  * enhancement: backtraces involving frames from the default evaluator are
    more readable.
  * enhancement: RUN-PROGRAM works with user-defined binary input and output
    streams.
  * enhancement: more informative compile-time warnings and runtime errors for
    type-errors detected at compile-time.
  * enhancement: deadlock detection for mutexes and spinlocks.
  * enhancement: dynamic-extent for &rest lists stack allocate only their
    spines, not their argumets. While portable code should not rely on this,
    particularly in combination with inlining, it should make dynamic-extent
    easier to use safely.
  * enhancement: SB-POSIX improvements:
    ** WNOHANG and WUNTRACED are exported.
    ** SYSCALL-ERROR now also provides the name of the failing system call.
  * enhancement: --script improvements:
    ** errors on standard input, output, and error streams are handled and
       cause scripts to exit silently, making them easier to use in shell
       pipelines.
    ** backtraces from scripts now go to standard error instead of the
       terminal even if one is available.
    ** --script can be an argument, causing the script to be loaded from
       standard input.
  * enhancement: MAKE-ALIEN-STRING provides an easy way to transport lisp
    strings to foreign memory.
  * enhancement: (SETF GC-LOGFILE) allows logging garbage collections to
    a file, making it easier to understand heap dynamics.
  * optimization: using a &REST argument only in APPLY or VALUES-LIST calls
    allows the compiler to automatically elide rest-list allocation so long as
    the call sites are in functions that the compiler knows cannot escape.
    (lp#504575)
  * optimization: CALL-NEXT-METHOD using explicit arguments is faster,
    especially in safe code when none of the required arguments have changed
    their identities.
  * bug fix: blocking reads from FIFOs created by RUN-PROGRAM were
    uninterruptible, as well as blocking reads from socket streams created
    with for which :SERVE-EVENTS NIL. (regression from 1.0.42.43)
  * bug fix: SET-SYNTAX-FROM-CHAR now removes dispatch-macro character syntax
    from the to-char if the from-char is not a dispatch-macro character.
  * bug fix: references to undefined variables in function calls that are
    optimized away now signal a runtime error. (lp#722734)
  * bug fix: miscompilation of MULTIPLE-VALUE-CALL when asserting derived
    types from a function defined in the same file. (regression from
    1.0.43.57)
  * bug fix: TRULY-THE forms are now macroexpandable and setf-expandable.
    (lp#771673)
  * bug fix: spurious errors during QUIT when standard streams were closed.