[clang] [CIR] Add support for AST call expressions on cir.call (PR #207261)

[Andy Kaylor via cfe-commits]

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@@ -1684,6 +1684,10 @@ def CIR_ASTVarDeclAttr : CIR_AST<"VarDecl", "var.decl", [
   ASTVarDeclInterface
 ]>;
 
+def CIR_ASTCallExprAttr : CIR_AST<"CallExpr", "call.expr", [
+  ASTCallExprInterface
----------------
andykaylor wrote:

Rithik and I talked about this earlier today, and I said then that I thought it was OK to go ahead with this under the understanding that the AST hook is just a temporary workaround until we know exactly what we need from the AST, but since then I've looked at how the incubator IdiomIdentifier pass is using it, and I think maybe it's better to handle it without the AST node, adding special attributes as we need them.

@SharmaRithik Look at how `CXXSpecialMemberAttr` is currently implemented on `cir::FuncOp`. I think we probably want something similar to that with optional call information on `CallOpBase`. For the things currently implemented in IdiomRecognizer and LibOpt, I think `isCalleeInStdNamespace` is really all you need. The rest can be deduced from that.

https://github.com/llvm/llvm-project/pull/207261