Add diagnostic output for fatal error before assert(false) call.

Former-commit-id: 4546fff20719e9be6dc9ca672ed12aa4304c880a

src/base/SMPInstr.cpp

@@ -4687,6 +4687,13 @@ bool SMPInstr::MDNormalizeStackOps(bool UseFP, STARS_sval_t FPDelta, bool Recomp
 							this->USEMemOp = NewOp;
 						}
 						else {
+							SMP_msg("\nFATAL ERROR in MDNormalizeStackOps: Stack operand is not the USEMemOp. Inst dump follows.\n");
+							SMP_msg("Stack Op: ");
+							PrintOperand(OldOp);
+							SMP_msg("   USEMemOp: ");
+							PrintOperand(this->USEMemOp);
+							SMP_msg(" \n");
+							this->Dump();
 							assert(false);
 						}
 					}