All VOPs that call allocation should save any live registers.
Rearrange the fpu save/restore stuff to make it a bit simpler.
Oops.  Need to use long long's to compute the age in gen_av_mem_age().
Clean up alloc overflow routine.  Cross-compile needed.

src/bootfiles/20c/boot-2012-07-1-x86-cross.lisp:
o X86 cross-compile script

src/compiler/x86/macros.lisp:
o New inline-allocation to call our new overflow routine.

src/lisp/x86-assem.S:
o New alloc_overflow routine.

src/tools/cross-scripts/cross-x86-x86.lisp:
o Export all symbols in VM that are external symbols in OLD-VM with
  the corresponding symbol name.
Remove old inline allocation function and corresponding assembly routines.
Clean up not-inline-allocation.

src/lisp/x86-assem.S:
o Remove the (now) unused alloc_to_<reg> functions.

src/compiler/x86/macros.lisp:
o Simplify the not-inline-allocation to use the same routines as
  inline allocation.
Change url to www.cmucl.org.
Clean up and correct some comments.
Fix possible stack corruption caused by possibly not allocating enough
stack space to hold the SSE2 state.  (Forgot to add extra bytes for
16-byte alignment!)
Add -R option to force recompilation of C runtime.
Fix ticket:61, using option 2.

src/lisp/gencgc.c:
o Save and restore the FPU state in alloc().

src/compiler/x86/alloc.lisp
src/compiler/x86/array.lisp
src/compiler/x86/call.lisp
src/compiler/x86/float-sse2.lisp
src/compiler/x86/float.lisp
src/compiler/x86/move.lisp
src/compiler/x86/sap.lisp:
o Don't need to use :save-p anymore because the allocation routine
  saves an live registers anyway.  This improves code generation as
  well.

src/general-info/release-20d.txt:
o Update.
Remove comment about compiling with clang, which now works fine.
Update to asdf 2.23.
 * Remove comments about gcc-4.2.  gcc or clang should work.
 * Min OSX version is 10.5 now.  Don't have access to anything older
   than 10.5 anyway.
Recognize x86_64 (for OSX Lion).
Update.
Merge branch 'master' of ssh://common-lisp.net/var/git/projects/cmucl/cmucl
Add note that OSX Lion can compile cmucl.
Add note that OSX 10.4 is no longer supported.
Support Lion and Mountain Lion which return x86-64 for uname -m.