Removed OpLessOrGreater (#2527)

Original commit:
KhronosGroup/SPIRV-LLVM-Translator@433ae975c2d10fb

Author: vmaksimo

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

@@ -977,6 +977,9 @@ class SPIRVCompare : public SPIRVInstTemplateBase {
       ResTy = Type;
     }
     assert(isCmpOpCode(OpCode) && "Invalid op code for cmp inst");
+    if (OpCode == OpLessOrGreater)
+      assert(this->getModule()->getSPIRVVersion() <= VersionNumber::SPIRV_1_5 &&
+             "OpLessOrGreater is removed starting from SPIR-V 1.6");
     assert((ResTy->isTypeBool() || ResTy->isTypeInt()) &&
            "Invalid type for compare instruction");
     assert(Op1Ty == Op2Ty && "Inconsistent types");