[llvm] [PowerPC] Add error for incorrect use of memory operands (PR #114277)

[Hubert Tong via llvm-commits]

================
@@ -99,10 +100,14 @@ struct PPCOperand;
 class PPCAsmParser : public MCTargetAsmParser {
   bool IsPPC64;
 
+  bool UsesMemOp;
----------------
hubert-reinterpretcast wrote:

I don't think this statefulness is good. Instead of trying to record (in an instance variable of the parser) that a memory operand was encountered, perhaps it is possible to instead mark the "operand" that is created to represent the base register of the memory operand.

https://github.com/llvm/llvm-project/pull/114277