headers: Add iwscapi.idl Required for https://github.com/mozilla/gecko-dev/blob/7e0ae4372c52b8183d1178132dd6493edb576738/xpcom/base/nsSystemInfo.cpp#L28 Signed-off-by: Biswapriyo Nath <nathbappai@gmail.com> Signed-off-by: LIU Hao <lh_mouse@126.com>