[PowerPC] Fix hi/lo encoding in old-style code emitter

This patch implements the equivalent change to r182091/r182092
in the old-style code emitter.  Instead of having two separate
16-bit immediate encoding routines depending on the instruction,
this patch introduces a single encoder that checks the machine
operand flags to decide whether the low or high half of a
symbol address is required.

Since now both encoders make no further distinction between
"symbolLo" and "symbolHi", the .td operand can now use a
single getS16ImmEncoding method.

Tested by running the old-style JIT tests on 32-bit Linux.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182097 91177308-0d34-0410-b5e6-96231b3b80d8
r182085 introduced a change that triggered an assertion on ARM. This is an immediate fix
which doesn't resolve the deeper problem.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182098 91177308-0d34-0410-b5e6-96231b3b80d8
LoopVectorize: Simplify code. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182100 91177308-0d34-0410-b5e6-96231b3b80d8
FileCheckize test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182101 91177308-0d34-0410-b5e6-96231b3b80d8
X86: Make shuffle -> shift conversion more aggressive about undefs.

Shuffles that only move an element into position 0 of the vector are common in
the output of the loop vectorizer and often generate suboptimal code when SSSE3
is not available. Lower them to vector shifts if possible.

We still prefer palignr over psrldq because it has higher throughput on
sandybridge.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182102 91177308-0d34-0410-b5e6-96231b3b80d8