ffi.c (ffi_call_win32): Add new argument to prototype for specify calling-convention.

ffi.c (ffi_call_win32): Add new argument to prototype for specify calling-convention.

        * src/libffi/src/x86/ffi.c (ffi_call_win32): Add new
        argument to prototype for specify calling-convention.
        (ffi_call): Add support for stdcall/thiscall convention.
        (ffi_prep_args): Likewise.
        (ffi_raw_call): Likewise.
        * src/x86/ffitarget.h (ffi_abi): Add FFI_THISCALL and
        FFI_FASTCALL.
        * src/x86/win32.S (_ffi_call_win32): Add support for
        fastcall/thiscall calling-convention calls.
        * testsuite/libffi.call/fastthis1_win32.c: New test.
        * testsuite/libffi.call/fastthis2_win32.c: New test.
        * testsuite/libffi.call/fastthis3_win32.c: New test.
        * testsuite/libffi.call/strlen2_win32.c: New test.
        * testsuite/libffi.call/many2_win32.c: New test.
        * testsuite/libffi.call/struct1_win32.c: New test.
        * testsuite/libffi.call/struct2_win32.c: New test.

From-SVN: r183676