[clang] Implement `ByteAddressBuffer` Load/Store methods (PR #176058)

[Kaitlin Peng via cfe-commits]

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@@ -1145,6 +1178,92 @@ BuiltinTypeDeclBuilder &BuiltinTypeDeclBuilder::addLoadMethods() {
   return *this;
 }
 
+BuiltinTypeDeclBuilder &
+BuiltinTypeDeclBuilder::addByteAddressBufferLoadMethods() {
+  assert(!Record->isCompleteDefinition() && "record is already complete");
+
+  using PH = BuiltinTypeMethodBuilder::PlaceHolder;
+  ASTContext &AST = SemaRef.getASTContext();
+
+  auto addLoadMethod = [&](StringRef MethodName, QualType ReturnType) {
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kmpeng wrote:

Ah yeah, I didn't want to name it that because there's already a `BuiltinTypeDeclBuilder::addLoadMethods()` and I thought it would be confusing. I probably need to find a better name or see if I can modify + use the existing one...

https://github.com/llvm/llvm-project/pull/176058