Add -miphonesimulator-version-min as alias to -ios-simulator-version-min.

Summary:
For better or worse the OS X command line tools refer to the iOS simulator as iphonesimucator. We should provide an alias flag -miphonesimulator-version-min that matches a consistent pattern with the other tools.

This is in the interest of making it easier for people to write platform-agnostic darwin build scripts.

Reviewers: bob.wilson, bogner

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D10743

llvm-svn: 240686