[clang] [flang][driver] Mark -fcommon and -mtune as visible in Flang (PR #68657)

[Fangcao Wang via cfe-commits]

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@@ -10,6 +10,9 @@
 ! Make sure that `-L' is "visible" to Flang's driver
 ! RUN: %flang -L/ -### %s
 
+! Make sure that `-fcommon' is "visible" to Flang's driver
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LittleMeepo wrote:

So should I put the test for this option somewhere else, or should I still put it in this file?

https://github.com/llvm/llvm-project/pull/68657