MachineFunctionProperties/MIRParser: Rename AllVRegsAllocated->NoVRegs, compute it

Rename AllVRegsAllocated to NoVRegs. This avoids the connotation of
running after register and simply describes that no vregs are used in
a machine function. With that we can simply compute the property and do
not need to dump/parse it in .mir files.

Differential Revision: http://reviews.llvm.org/D23850

llvm-svn: 279698
diff --git a/llvm/lib/CodeGen/VirtRegMap.cpp b/llvm/lib/CodeGen/VirtRegMap.cpp
index fcba8ad..57aa740 100644
--- a/llvm/lib/CodeGen/VirtRegMap.cpp
+++ b/llvm/lib/CodeGen/VirtRegMap.cpp
@@ -177,7 +177,7 @@
   bool runOnMachineFunction(MachineFunction&) override;
   MachineFunctionProperties getSetProperties() const override {
     return MachineFunctionProperties().set(
-        MachineFunctionProperties::Property::AllVRegsAllocated);
+        MachineFunctionProperties::Property::NoVRegs);
   }
 };
 } // end anonymous namespace