[clang] [CIR] Upstream overflow builtins (PR #166643)

[Andy Kaylor via cfe-commits]

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@@ -502,6 +530,154 @@ RValue CIRGenFunction::emitBuiltinExpr(const GlobalDecl &gd, unsigned builtinID,
     cir::PrefetchOp::create(builder, loc, address, locality, isWrite);
     return RValue::get(nullptr);
   }
+  case Builtin::BI__builtin_add_overflow:
+  case Builtin::BI__builtin_sub_overflow:
+  case Builtin::BI__builtin_mul_overflow: {
+    const clang::Expr *LeftArg = e->getArg(0);
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andykaylor wrote:

You've still got variables in this file starting with uppercase letters. They should start with lowercase.

https://github.com/llvm/llvm-project/pull/166643