[llvm] [SPIR-V] Do not reassign kernel arg SPIRVType based on later calls/uses (PR #75514)

[Nathan Gauër via llvm-commits]

================
@@ -265,6 +281,85 @@ Instruction *SPIRVEmitIntrinsics::visitBitCastInst(BitCastInst &I) {
   return NewI;
 }
 
+void SPIRVEmitIntrinsics::insertPtrCastInstr(Instruction *I) {
+  Value *Pointer;
+  Type *ExpectedElementType;
+  unsigned OperandToReplace;
+  if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
+    Pointer = SI->getPointerOperand();
+    ExpectedElementType = SI->getValueOperand()->getType();
+    OperandToReplace = 1;
+  } else if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
+    Pointer = LI->getPointerOperand();
+    ExpectedElementType = LI->getType();
+    OperandToReplace = 0;
+  } else if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(I)) {
+    Pointer = GEPI->getPointerOperand();
+    ExpectedElementType = GEPI->getSourceElementType();
+    OperandToReplace = 0;
+  } else {
+    return;
+  }
+
+  // If Pointer is the result of nop BitCastInst (ptr -> ptr), use the source
+  // pointer instead. The BitCastInst should be later removed when visited.
+  if (BitCastInst *BC = dyn_cast<BitCastInst>(Pointer))
----------------
Keenuts wrote:

Shouldn't this be:
```cpp
while (BitCastInst *BC = dyn_cast<BitCastInst>)
    Pointer = BC->getOperand(0);
```

Otherwise, the bitcast isn't properly added if I change the `uitofp-with-bool.ll` test to:

```llvm
  %AA = bitcast float addrspace(1)* %A to i32 addrspace(1)*
  %AAA = bitcast i32 addrspace(1)* %AA to float addrspace(1)*
  store float %conv, float addrspace(1)* %AAA, align 4;
  ;store float %conv, float addrspace(1)* %A, align 4;
```

https://github.com/llvm/llvm-project/pull/75514