Switch all register list clients to the new MC*Iterator interface.

No functional change intended.

Sorry for the churn. The iterator classes are supposed to help avoid
giant commits like this one in the future. The TableGen-produced
register lists are getting quite large, and it may be necessary to
change the table representation.

This makes it possible to do so without changing all clients (again).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157854 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/RegAllocBase.cpp

@@ -239,9 +239,9 @@ void RegAllocBase::allocatePhysRegs() {
 // physical register. Return the interfering register.
 unsigned RegAllocBase::checkPhysRegInterference(LiveInterval &VirtReg,
                                                 unsigned PhysReg) {
-  for (const uint16_t *AliasI = TRI->getOverlaps(PhysReg); *AliasI; ++AliasI)
-    if (query(VirtReg, *AliasI).checkInterference())
-      return *AliasI;
+  for (MCRegAliasIterator AI(PhysReg, TRI, true); AI.isValid(); ++AI)
+    if (query(VirtReg, *AI).checkInterference())
+      return *AI;
   return 0;
 }