Implement ABIArgType::Coerce support.   - As a test, enable basic usage for some common x86-32 cases. This     increases our x86-32 compliance (on other targets our compliance     will just be broken in a different way).
Implement ABIArgType::Coerce support.
  - As a test, enable basic usage for some common x86-32 cases. This
    increases our x86-32 compliance (on other targets our compliance
    will just be broken in a different way).


git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@56051 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang