[llvm] Reland [CGData] llvm-cgdata #89884 (PR #101461)

[Kyungwoo Lee via llvm-commits]

================
@@ -0,0 +1,28 @@
+include "llvm/Option/OptParser.td"
+
+class F<string letter, string help> : Flag<["-"], letter>, HelpText<help>;
----------------
kyulee-com wrote:

Updated by using two dashes for the long options while using single dash for the short (alias) option.

https://github.com/llvm/llvm-project/pull/101461