Tell the register allocator about new unused virtual registers.

This allows the allocator to free any resources used by the virtual register,
including physical register assignments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127560 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/InlineSpiller.cpp b/lib/CodeGen/InlineSpiller.cpp
index 8964853..1b1cd68 100644
--- a/lib/CodeGen/InlineSpiller.cpp
+++ b/lib/CodeGen/InlineSpiller.cpp
@@ -573,5 +573,6 @@
     MI->eraseFromParent();
   }
 
-  // FIXME: Notify the register allocator that the snippets are now dead.
+  for (unsigned i = 0, e = RegsToSpill.size(); i != e; ++i)
+    edit.eraseVirtReg(RegsToSpill[i], lis_);
 }