Remove comparison methods for MVT.  The main cause
of apint codegen failure is the DAG combiner doing
the wrong thing because it was comparing MVT's using
< rather than comparing the number of bits.  Removing
the < method makes this mistake impossible to commit.
Instead, add helper methods for comparing bits and use
them.

llvm-svn: 52098
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 774988a..81cdf46 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -384,7 +384,7 @@
 
   MVT DestVT = getTypeToTransformTo(NewVT);
   RegisterVT = DestVT;
-  if (DestVT < NewVT) {
+  if (DestVT.bitsLT(NewVT)) {
     // Value is expanded, e.g. i64 -> i16.
     return NumVectorRegs*(NewVT.getSizeInBits()/DestVT.getSizeInBits());
   } else {