* src/prep_cif.c (ffi_prep_cif): Allow for X86_WIN32
        also FFI_THISCALL.
        * src/x86/ffi.c (ffi_closure_THISCALL): Add prototype.
        (FFI_INIT_TRAMPOLINE_THISCALL): New trampoline code.
        (ffi_prep_closure_loc): Add FFI_THISCALL support.
        * src/x86/ffitarget.h (FFI_TRAMPOLINE_SIZE): Adjust size.
        * src/x86/win32.S (ffi_closure_THISCALL): New closure code
        for thiscall-calling convention.
        * testsuite/libffi.call/closure_thiscall.c: New test.

From-SVN: r184021