[AVX] Create Inits Via Factory Method

Replace uses of new *Init with *Init::get.  This hides the allocation
implementation so that we can unique Inits in various ways.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136486 91177308-0d34-0410-b5e6-96231b3b80d8

utils/TableGen/CodeEmitterGen.cpp

@@ -56,7 +56,7 @@ void CodeEmitterGen::reverseBits(std::vector<Record*> &Insts) {
       NewBits[middle] = BI->getBit(middle);
     }
 
-    BitsInit *NewBI = new BitsInit(ArrayRef<const Init *>(NewBits));
+    const BitsInit *NewBI = BitsInit::get(NewBits);
 
     // Update the bits in reversed order so that emitInstrOpBits will get the
     // correct endianness.