[win32] Generic change in win32 branch: don't just turn on CRIPPLED_CC

[win32] Generic change in win32 branch: don't just turn on CRIPPLED_CC
when USE_THREADS.  GCC for instance, can do without macros that use
globals.  Instead, selectively re#define only those macros
that use globals to their functional equivalents.  Tests 100% on
Solaris/gcc (after `chmod +x t/op/nothread.t t/lib/thread.t` (hint,hint)).

p4raw-id: //depot/win32/perl@276