Implement aarch64 neon instruction set AdvSIMD (3V Diff), covering the following 26 instructions,

SADDL, UADDL, SADDW, UADDW, SSUBL, USUBL, SSUBW, USUBW, ADDHN, RADDHN, SABAL, UABAL, SUBHN, RSUBHN, SABDL, UABDL, SMLAL, UMLAL, SMLSL, UMLSL, SQDMLAL, SQDMLSL, SMULL, UMULL, SQDMULL, PMULL



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190288 91177308-0d34-0410-b5e6-96231b3b80d8
Generate compact unwind encoding from CFI directives.

We used to generate the compact unwind encoding from the machine
instructions. However, this had the problem that if the user used `-save-temps'
or compiled their hand-written `.s' file (with CFI directives), we wouldn't
generate the compact unwind encoding.

Move the algorithm that generates the compact unwind encoding into the
MCAsmBackend. This way we can generate the encoding whether the code is from a
`.ll' or `.s' file.

<rdar://problem/13623355>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190290 91177308-0d34-0410-b5e6-96231b3b80d8