Fix monodis compilation on mingw which is missing some fp classification functions.
Fix mingw compilation problems.
Remove the usage of gcc-3 on mingw, the gcc-3 package no longer exists on cygwin. Mono can be built by configuring with --host=i686-pc-mingw32. Building without this will not work, since the libtool wrapper executables created by libtool will be unusable, i.e. they exit before the real runtime process exits.
Avoid infinite logfiles if the test-process-exit test fails to terminate.
[sgen] Disable freeing of OS memory on win32, it causes asserts because VirtualFree () fails.
Fix a regression introduced by d84a165c8e799d8734df5f51a6dcf12b1f2a3695. Unbox casts were failing for enums. Fixes #14026.