[analyzer] Fix unused variable warnings in Release builds
[analyzer] Fix unused variable warnings in Release builds

This was just an inlined version of isa<CXXConstructExpr>. NFC.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@351007 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang