win32: for strict ANSI

* thread_win32.c (w32_thread_start_func, thread_start_func_1),
  (timer_thread_func): use __stdcall instead of _stdcall which is
  unavailable in strict ANSI mode.  [ruby-core:55312] [Bug #8495]
* win32/win32.c (gettimeofday): use __cdecl instead of _cdecl.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41834 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
numeric.c: for strict ANSI

* numeric.c (finite): add declaration for strict ANSI.
  [ruby-core:55312] [Bug #8495]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41835 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
win32.c: for strict ANSI

* win32/win32.c (rb_w32_pow): move from win32.h and disable strict
  ANSI mode macro to let _controlfp() stuff defined.
  [ruby-core:55312] [Bug #8495]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41836 b2dd03c8-39d4-4d8f-98ff-823fe69b080e