Switch to gold linker on android x86, x86_64, arm
Switch to gold linker on android x86, x86_64, arm

These architectures already using the gold linker for the android
framework and switching to gold gives us the opportunity to enable ICF.

Safe ICF (identical code folding) reduces the size of an optimized and
striped binary by ~5%.

Differential revision: http://reviews.llvm.org/D15379

git-svn-id: 4c4cc70b1ef44ba2b7963015e681894188cea27e@255240 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-lldb,llvm-mirror/lldb,llvm-mirror/lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,llvm-mirror/lldb,llvm-mirror/lldb,apple/swift-lldb,apple/swift-lldb,llvm-mirror/lldb