[AArch64] Disable some optimization cases for type conversion from sint to fp, because those optimization cases are micro-architecture dependent and only make sense for Cyclone. A new predicate Cyclone is introduced in .td file.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213827 91177308-0d34-0410-b5e6-96231b3b80d8