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/RegAllocFast.cpp b/lib/CodeGen/RegAllocFast.cpp
index 8a22e63..2cb16e0 100644
--- a/lib/CodeGen/RegAllocFast.cpp
+++ b/lib/CodeGen/RegAllocFast.cpp
@@ -354,8 +354,8 @@
   }
 
   // Maybe a superregister is reserved?
-  for (const uint16_t *AS = TRI->getAliasSet(PhysReg);
-       unsigned Alias = *AS; ++AS) {
+  for (MCRegAliasIterator AI(PhysReg, TRI, false); AI.isValid(); ++AI) {
+    unsigned Alias = *AI;
     switch (PhysRegState[Alias]) {
     case regDisabled:
       break;
@@ -408,8 +408,8 @@
 
   // This is a disabled register, disable all aliases.
   PhysRegState[PhysReg] = NewState;
-  for (const uint16_t *AS = TRI->getAliasSet(PhysReg);
-       unsigned Alias = *AS; ++AS) {
+  for (MCRegAliasIterator AI(PhysReg, TRI, false); AI.isValid(); ++AI) {
+    unsigned Alias = *AI;
     switch (unsigned VirtReg = PhysRegState[Alias]) {
     case regDisabled:
       break;
@@ -456,8 +456,8 @@
   // This is a disabled register, add up cost of aliases.
   DEBUG(dbgs() << PrintReg(PhysReg, TRI) << " is disabled.\n");
   unsigned Cost = 0;
-  for (const uint16_t *AS = TRI->getAliasSet(PhysReg);
-       unsigned Alias = *AS; ++AS) {
+  for (MCRegAliasIterator AI(PhysReg, TRI, false); AI.isValid(); ++AI) {
+    unsigned Alias = *AI;
     if (UsedInInstr.test(Alias))
       return spillImpossible;
     switch (unsigned VirtReg = PhysRegState[Alias]) {