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
diff --git a/lib/CodeGen/RegAllocBasic.cpp b/lib/CodeGen/RegAllocBasic.cpp
index 6b01ccb..83dbbf2 100644
--- a/lib/CodeGen/RegAllocBasic.cpp
+++ b/lib/CodeGen/RegAllocBasic.cpp
@@ -204,8 +204,8 @@
   // either the union or live intervals.
   unsigned NumInterferences = 0;
   // Collect interferences assigned to any alias of the physical register.
-  for (const uint16_t *asI = TRI->getOverlaps(PhysReg); *asI; ++asI) {
-    LiveIntervalUnion::Query &QAlias = query(VirtReg, *asI);
+  for (MCRegAliasIterator AI(PhysReg, TRI, true); AI.isValid(); ++AI) {
+    LiveIntervalUnion::Query &QAlias = query(VirtReg, *AI);
     NumInterferences += QAlias.collectInterferingVRegs();
     if (QAlias.seenUnspillableVReg()) {
       return false;
@@ -216,8 +216,8 @@
   assert(NumInterferences > 0 && "expect interference");
 
   // Spill each interfering vreg allocated to PhysReg or an alias.
-  for (const uint16_t *AliasI = TRI->getOverlaps(PhysReg); *AliasI; ++AliasI)
-    spillReg(VirtReg, *AliasI, SplitVRegs);
+  for (MCRegAliasIterator AI(PhysReg, TRI, true); AI.isValid(); ++AI)
+    spillReg(VirtReg, *AI, SplitVRegs);
   return true;
 }