Override isILOpCodeSupported on x86

Now that we have an evaluator for each and every IL opcode, we can no
longer compare against `unImpOpEvaluator` or `badILOpEvaluator` to
determine whether we have implemented an evaluator for that specific IL.

Instead we have to override this function and manually return false
for the specific set of unimplemented opcodes.

compiler/x/codegen/OMRCodeGenerator.cpp

@@ -1095,6 +1095,18 @@ OMR::X86::CodeGenerator::supportsNonHelper(TR::SymbolReferenceTable::CommonNonhe
       }
    }
 
+bool
+OMR::X86::CodeGenerator::isILOpCodeSupported(TR::ILOpCodes o)
+   {
+   switch(o)
+      {
+      case TR::a2i:
+         return false;
+      default:
+         return OMR::CodeGenerator::isILOpCodeSupported(o);
+      }
+   }
+
 TR::RealRegister *
 OMR::X86::CodeGenerator::getMethodMetaDataRegister()
    {

compiler/x/codegen/OMRCodeGenerator.hpp

@@ -366,6 +366,8 @@ class OMR_EXTENSIBLE CodeGenerator : public OMR::CodeGenerator
    virtual bool getSupportsBitPermute();
 
    bool supportsNonHelper(TR::SymbolReferenceTable::CommonNonhelperSymbol symbol);
+
+   static bool isILOpCodeSupported(TR::ILOpCodes);
 
    bool hasTMEvaluator()                       {return true;}