Fix build warnings

Found*contractedFMulAdd became unused after commit e89518b ("Enable
strict rules to set ContractionOFF (#521)", 2020-05-20).

Add a missing override to suppress a -Winconsistent-missing-override
warning.

Author: svenvh

llvm-spirv/lib/SPIRV/SPIRVLowerOCLBlocks.cpp

@@ -79,7 +79,7 @@ class SPIRVLowerOCLBlocks : public ModulePass {
     return "Lower OpenCL Blocks For SPIR-V";
   }
 
-  bool runOnModule(Module &M) {
+  bool runOnModule(Module &M) override {
     bool Changed = false;
     for (Function &F : M) {
       if (!isBlockInvoke(F))

llvm-spirv/lib/SPIRV/libSPIRV/SPIRVFunction.h

@@ -167,9 +167,6 @@ class SPIRVFunction : public SPIRVValue, public SPIRVComponentExecutionModes {
   std::vector<const SPIRVValue *> Variables;
   typedef std::vector<SPIRVBasicBlock *> SPIRVLBasicBlockVector;
   SPIRVLBasicBlockVector BBVec;
-
-  bool FoundUncontractedFMulAdd = false;
-  bool FoundContractedFMulAdd = false;
 };
 
 typedef SPIRVEntryOpCodeOnly<OpFunctionEnd> SPIRVFunctionEnd;