Revert "SPIRV: Set NoPHIs property after selection"

This reverts commit 5529880.

Author: arsenm

llvm/lib/Target/SPIRV/SPIRVTargetMachine.cpp

@@ -269,12 +269,6 @@ class SPIRVInstructionSelect : public InstructionSelect {
     return InstructionSelect::getRequiredProperties().reset(
         MachineFunctionProperties::Property::RegBankSelected);
   }
-
-  MachineFunctionProperties getClearedProperties() const override {
-    // No generic Phis remain, replaced with OpPhi
-    return InstructionSelect::getClearedProperties().reset(
-        MachineFunctionProperties::Property::NoPHIs);
-  }
 };
 } // namespace