Please update docs for fuse-ctor-homing

[rnk]

These docs look stale: https://clang.llvm.org/docs/UsersManual.html#cmdoption-fuse-ctor-homing "This flag is not enabled by default, and needs to be used with -cc1 or -Xclang."

I believe it is enabled by default at this point. I wasn't able to find it in any past release notes, though.