[llvm] [AMDGPU] MCExpr-ify MC layer kernel descriptor (PR #80855)

[Matt Arsenault via llvm-commits]

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@@ -420,38 +421,41 @@ uint16_t AMDGPUAsmPrinter::getAmdhsaKernelCodeProperties(
   return KernelCodeProperties;
 }
 
-amdhsa::kernel_descriptor_t AMDGPUAsmPrinter::getAmdhsaKernelDescriptor(
-    const MachineFunction &MF,
-    const SIProgramInfo &PI) const {
+MCKernelDescriptor
+AMDGPUAsmPrinter::getAmdhsaKernelDescriptor(const MachineFunction &MF,
+                                            const SIProgramInfo &PI) const {
   const GCNSubtarget &STM = MF.getSubtarget<GCNSubtarget>();
   const Function &F = MF.getFunction();
   const SIMachineFunctionInfo *Info = MF.getInfo<SIMachineFunctionInfo>();
 
-  amdhsa::kernel_descriptor_t KernelDescriptor;
-  memset(&KernelDescriptor, 0x0, sizeof(KernelDescriptor));
+  auto CreateExpr = [&MF](int64_t Value) {
+    return MCConstantExpr::create(Value, MF.getContext());
+  };
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arsenm wrote:

It's less noisy if you pull the MF.getContext() into a variable 

https://github.com/llvm/llvm-project/pull/80855