LivePhysRegs: removeReg() must remove aliased registers

We must remove all aliased registers which may be more than the all sub
and super registers combined.

Bug found while reading the code. The bug does not affect any existing
target as the only use of register aliases I could found were control
registers on ARM and Hexagon which are all reserved.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265510 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/LivePhysRegs.h

@@ -84,12 +84,8 @@ class LivePhysRegs {
   void removeReg(unsigned Reg) {
     assert(TRI && "LivePhysRegs is not initialized.");
     assert(Reg <= TRI->getNumRegs() && "Expected a physical register.");
-    for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
-         SubRegs.isValid(); ++SubRegs)
-      LiveRegs.erase(*SubRegs);
-    for (MCSuperRegIterator SuperRegs(Reg, TRI, /*IncludeSelf=*/false);
-         SuperRegs.isValid(); ++SuperRegs)
-      LiveRegs.erase(*SuperRegs);
+    for (MCRegAliasIterator R(Reg, TRI, true); R.isValid(); ++R)
+      LiveRegs.erase(*R);
   }
 
   /// \brief Removes physical registers clobbered by the regmask operand @p MO.