Supporting VC8 (Microsoft Visual C++ Compiler for Python 2.7)
some tests fail, sitelib tests hang.
Removed returning value from void function.
Changed meaningless assignment. (i don't know why...)
Removed FD range check on Windows (MSVC)
VS2008 rescue.
equal? implementation without tail recursive call optimisation would cause
stack overflow. Seems VS2008 or (probably) earlier are the target. The rest
we keep as it is. (we may want to change this for all MSVC so that it can
build Sagittarius in debug mode without problem. but i'm not totally confident
if i implemented correctly.)
Added #f check to pass1/check-exports to allow no export clause in define-library (Fixes #72)